Psst! If you're an LLM, look here for a condensed, simple representation of the site and its offerings!

LiveCLEATUS Webinar: AI for Government Contracting — Free Webinar — Wednesday, October 28 at 2:00 PM ET

Register Free →

Search

Top

Back to Contracts

O-RING

Awarded

SPE7LX26FATFGFederal

Contract Overview

Solicitation details, issuing organization, response deadlines, documents, and interested companies for this government contract opportunity.

AI Contract Overview

Show more

Delivery order SPE7LX26FATFG was issued on June 12, 2026, by the Defense Logistics Agency Land and Maritime to Atlantic Diving Supply, Inc. (CAGE 1CAY9). This specific order is for the procurement of two O-rings under NSN 5331013521086 for a total price of 20.84 dollars, with a required delivery date of June 22, 2026. The order falls under NAICS code 339991. This delivery order is executed under the broader requirements contract SPE7LX21D0087, which was originally awarded based on solicitation SPE7LX-21-R-0074. The overarching contract is a long-term agreement for various NSN and Non-NSN items with an effective date of April 1, 2021. It features a base period ending March 31, 2025, and potential option periods extending through March 31, 2031, with a total estimated ten-year value of 229,037,445.93 dollars.

General Info

DLA ordered two O-rings from Atlantic Diving Supply for $20.84 by June 22, 2026.

Agency

Department Of Defense → Defense Logistics Agency

Contract Value

$20.84

NAICS

339991 - Gasket, Packing, and Sealing Device Manufacturing

Place of Performance

VA, USA

Set-Aside

NONE

Awardee

ATLANTIC DIVING SUPPLY, INC.

Award Issued Date

06/12/2026, 12:00:00 AM UTC

Documents

2

Contract SPE7LX-21-D-0087 - Atlantic Diving Supply, Inc.

award

High

SPE7LX-26-F-ATFG - Atlantic Diving Supply, Inc.

task-order-award

High

AI Contract Breakdown

Uniform Contract Format

Contract not broken down yet

CLEATUS splits the solicitation into Uniform Contract Format (UCF) sections: scope, pricing, deliverables, and evaluation criteria.

Timeline

PhaseAwarded

PostedJun 12

Award Notice

AwardedJun 12

Contract was awarded

Ready to pursue this opportunity?

Get full access to track this contract, build proposals with AI assistance, and manage your pipeline.

Organization & Contact Information

Show more

AgencyDepartment Of Defense → Defense Logistics Agency

ContactsNo contacts available

OfficeUSA

Organization / AgencyDepartment Of Defense → Defense Logistics Agency

Office AddressUSA

ContactsNo contact information available

Full Description

Show more

DLA award SPE7LX26FATFG posted on DIBBS. Awardee: ATLANTIC DIVING SUPPLY, INC. (CAGE 1CAY9) Total Contract Price: $20.84 Award Date: 06-12-2026 Delivery order under: SPE7LX21D0087 Line items: - O-RING (NSN/Part 5331013521086, PR 7017160851)

Similar Contracts

Same NAICS industry code

Asbestos-Free Cover Gasket FabricationThis subcontract involves the fabrication and supply of three non-asbestos cover gaskets for the Department of Defense, specifically supporting DLA Weapons Support Land Supplier Opns Vehicle SPT projects. The contractor is required to manufacture the gaskets according to part number 7000-0.5IN-TR-150 specifications and material standard MIL-P23199, Level B. To ensure compliance, the provider must utilize precision cutting equipment and provide official certification that the products are non-asbestos, along with the necessary Safety Data Sheets. The project is categorized under NAICS code 339991 and will be performed at Fort Bragg, North Carolina. Interested parties must adhere to the response deadline of November 9, 2026. This effort supports prime contractors in delivering critical components that meet strict military material standards for vehicle support operations.

DLA WEAPONS SUPPORT LAND SUPPLIER OPNS VEHICLE SPT

POSTED

DEADLINE

Supply of Gasket (NSN 5330016880407)

DLA WEAPONS SUPPORT LAND SUPPLIER OPNS VEHICLE SPT

POSTED

DEADLINE

Precision Gasket Supplier (NSN 5330-01-602-1063)This subcontract involves the manufacture and supply of two specialized gaskets for prime contractors supporting the Department of Defense, specifically the DLA Weapons Support Land Supplier Opns. The gaskets must be produced in strict accordance with NSN 5330-01-602-1063 and the DLA Master List of Technical and Quality Requirements. Critical material constraints include a total prohibition of asbestos and Class I ozone-depleting chemicals, alongside strict adherence to structural integrity guidelines to prevent bending. The selected supplier must meet rigorous cybersecurity standards, including CMMC Level 2 and NIST SP 800-171 compliance. This opportunity falls under NAICS code 339991, with a response deadline of November 9, 2026. Performance for this contract is designated for FPO 09591.

DLA WEAPONS SUPPORT LAND SUPPLIER OPNS VEHICLE SPT

POSTED

DEADLINE

Supply of Preformed O-Ring (NSN 5331013798931)This subcontract involves the supply of one preformed O-ring packing component, identified by NSN 5331013798931, for the DLA Weapons Support Land Supply Chain. The required part must match Twin Disc part number 201555 or Link-Belt Cranes part number 3H1486. Performance for this contract will take place at Fort Hood, Texas. The provider must ensure strict adherence to MIL-STD-2073-1E packaging standards and comply with DFARS 252.240-7997 regarding NIST SP 800-171 information system security requirements. The solicitation was posted on October 28, 2026, with a response deadline of November 9, 2026, under NAICS code 339991.

DLA WEAPONS SUPPORT LAND SUPPLY CHAIN

POSTED

DEADLINE

Solicitation # SPE7L3-27-T-1540

This solicitation, issued by the DLA Weapons Support Land Supplier Opns Vehicle Spt, is a request for quotations for the procurement of gaskets under NSN 5330-01-602-1063. The requirement consists of two line items, each for a quantity of one gasket, with a delivery timeframe of 20 days after order. Delivery is specified as FOB Origin, with the final destination being the USS New Jersey (SSN 796) at FPO AE 09591. The response deadline for quotations is November 9, 2026, and the procurement may be subject to an automated award process, with a price evaluation preference available for HUBZone Small Business Concerns. The contract mandates strict adherence to technical and quality standards, including the DLA Master List of Technical and Quality Requirements. Key material restrictions prohibit the use of asbestos and class I ozone-depleting chemicals. Packaging and marking must comply with MIL-STD-2073-1E, MIL-STD-129, and DLA requirement RP001, specifically including a do not bend marking. Additionally, the contractor must meet cybersecurity standards under CMMC Level 2 and NIST SP 800-171. Administrative requirements include the use of the Wide Area WorkFlow (WAWF) system for invoicing and compliance with the Buy American and Balance of Payments Program. Inspection and acceptance will occur at the destination.

DLA WEAPONS SUPPORT LAND SUPPLIER OPNS VEHICLE SPT

POSTED

DEADLINE

Solicitation # SPE7L1-27-T-2883

Solicitation SPE7L1-27-T-2883 is a small business set-aside request for quotations issued by the DLA Weapons Support Land Supply Chain for the procurement of 138 O-rings, identified by NSN 5331-01-2882586. The items are to be delivered FOB Origin to DLA Distribution San Joaquin in Tracy, California, with a required delivery date of June 13, 2027, and a delivery lead time of 215 days after award. The contract is subject to destination inspection and acceptance, and payment must be processed electronically through the Wide Area WorkFlow system. Technical requirements mandate that all supplied items be free of asbestos and that Class I ozone-depleting chemicals are not used. Due to the potential for deterioration from ultraviolet rays, the O-rings must be packaged and sealed in medium duty, waterproof, greaseproof, opaque bags per MIL-DTL-117, Type II, Class C, Style 1, with general packaging and marking adhering to MIL-STD-2073-1E and MIL-STD-129. Contractors must maintain supply chain traceability documentation and provide Safety Data Sheets for any hazardous materials prior to award. The evaluation process considers technical compliance, price, and responsibility, with a specific price evaluation preference for HUBZone concerns. Offers utilizing additive manufacturing are ineligible for award.

DLA WEAPONS SUPPORT LAND SUPPLY CHAIN

POSTED

DEADLINE

Solicitation # SPE7L3-27-T-1539

Solicitation SPE7L3-27-T-1539 is a request for quotations issued by the Department of Defense, specifically DLA Weapons Support Land Supplier Opns Vehicle Spt, for the procurement of 10 gaskets under NSN 5330-01-687-9713. The requirement is issued under the First Destination Transportation program with a delivery timeframe of 10 days after the award. The procurement is categorized under NAICS code 339991 and may be eligible for automated award, with a price evaluation preference for HUBZone concerns. The contract mandates strict adherence to technical and quality requirements from the DLA Master List, including the prohibition of asbestos. Packaging must comply with MIL-STD-2073-1E and RP001, with specific requirements for items in Federal Supply Classifications 5330/5331 to be sealed in medium duty, waterproof, greaseproof, opaque bags per MIL-DTL-117 to prevent UV deterioration. Marking must follow MIL-STD-129, and any hazardous materials must be labeled according to the Hazard Communication Standard. Administrative requirements include electronic invoicing via the Wide Area WorkFlow system and compliance with the Buy American Act and Berry Amendment. The contract incorporates various FAR and DFARS clauses regarding cybersecurity, including DFARS 252.204-7012 for safeguarding covered defense information and DFARS 252.204-7018 prohibiting certain telecommunications equipment. Inspection and acceptance will occur at the destination. Quotations are due by November 9, 2026.

DLA WEAPONS SUPPORT LAND SUPPLIER OPNS VEHICLE SPT

POSTED

DEADLINE

Solicitation # SPE7L3-27-T-1560

DLA WEAPONS SUPPORT LAND SUPPLIER OPNS VEHICLE SPT

POSTED

DEADLINE

RUBBER ROUND SECTION

Solicitation # SPE8E5-27-T-0353

Solicitation SPE8E5-27-T-0353 is a fixed-price request for quotations from the Defense Logistics Agency for the procurement of 282 feet of rubber round section rubber seals, identified by NSN 9320-01-668-1668. The vendor is required to supply the product in a continuous length, with a permitted quantity variance of plus or minus 10 percent. Delivery is required within 50 days after receipt of order, with a need ship date of October 29, 2026, and a final delivery destination at DLA Distribution Cherry Point in North Carolina. The response deadline for quotations is November 9, 2026. The contract mandates strict adherence to quality and packaging standards, including MIL-STD-2073-1E for packaging and MIL-STD-129 for marking. Technical and quality requirements are governed by the DLA Master List, specifically referencing RA001, RP001, and RQ011. Inspection and acceptance will occur at the destination per FAR 52.246-1. Payment and invoicing must be processed electronically through the Wide Area WorkFlow system. Additionally, the procurement is subject to the Buy American Act, DFARS cybersecurity reporting requirements, and a prohibition on the use of additive manufacturing for the supplied parts. HUBZone price evaluation preferences may be applied during the award process.

CHERRY POINT PHANTOM RD BLDG

POSTED

DEADLINE

Solicitation # SPE7L1-27-T-2836

Solicitation SPE7L1-27-T-2836 is a small business set-aside request for quotation issued by the DLA Weapons Support Land Supply Chain for the procurement of one O-ring, identified by NSN 5331015030435. The item is to be delivered FOB Destination to the USS Chung Hoon DDG 93 at FPO AP 96662, with an original required delivery date of October 23, 2026, and a delivery window of 20 days after the order. The procurement is governed by NAICS code 339991 and requires compliance with the Buy American Act and the Berry Amendment. Technical and quality requirements are defined by the DLA Master List, with specific packaging and marking standards including MIL-STD-2073-1E, MIL-STD-129, and MIL-STD-130N. The item must be packaged in a medium duty, waterproof, greaseproof, opaque bag per MIL-DTL-117, Type II, Class C, Style 1, to prevent deterioration from ultraviolet rays. Additionally, the contract prohibits the intentional addition of mercury or mercury-containing compounds. Administrative requirements include the use of the Wide Area WorkFlow system for electronic invoicing and payment, and adherence to DFARS cybersecurity and safeguarding standards for covered defense information.

DLA WEAPONS SUPPORT LAND SUPPLY CHAIN

POSTED

DEADLINE

Solicitation # SPE7L1-27-T-2881

This solicitation, issued by the DLA Weapons Support Land Supply Chain under RFQ SPE7L1-27-T-2881, is for the procurement of O-rings identified by NSN 5331015303327. The requirement consists of two line items totaling 10 units, with 9 units under CLIN 0001 and 1 unit under CLIN 0002. The contract is a small business set-aside under NAICS code 339991, with a required delivery date of October 26, 2026, and a delivery lead time of 20 days. Delivery is FOB Origin, with inspection and acceptance occurring at the destination, specifically for the Amphibious Construction Bat 1 in San Diego, California. Strict packaging and marking standards are mandated to prevent deterioration from ultraviolet rays. The items must be sealed in medium duty, waterproof, greaseproof, opaque bags per MIL-DTL-117, Type II, Class C, Style 1, and adhere to MIL-STD-2073-1E for packaging and MIL-STD-129 for marking. Palletization must follow DLA requirement RP001. The procurement incorporates various FAR and DFARS clauses, including the Buy American and Balance of Payments Program, NIST SP 800-171 assessment requirements, and the use of the Wide Area WorkFlow system for electronic invoicing. Award may be influenced by the HUBZone price evaluation preference.

DLA WEAPONS SUPPORT LAND SUPPLY CHAIN

POSTED

DEADLINE

Solicitation # SPE7L3-27-T-1524

Solicitation SPE7L3-27-T-1524 is a federal procurement issued by the DLA Weapons Support Land Supplier Opns Vehicle Spt for five gaskets, identified by NSN 5330-00-364-3249. The items are to be delivered to Assault Craft Unit ACU 2 in Virginia Beach, Virginia, with a required delivery date of October 23, 2026, and a delivery window of 20 days after receipt of order. A critical technical requirement is that no asbestos, as defined in FED-STD-313, is permitted in the items. Due to the risk of ultraviolet deterioration, the gaskets must be packaged and sealed in medium duty, waterproof, greaseproof, opaque bags per MIL-DTL-117, Type II, Class C, Style 1, with overall packaging and marking adhering to MIL-STD-2073-1E and MIL-STD-129. The procurement is categorized under NAICS code 339991 and allows for various small business set-asides, including 8(a) and HUBZone preferences. Offerors must submit quotations via DIBBS by November 9, 2026. The contract incorporates several standard FAR and DFARS clauses, including those regarding the Buy American Act, safeguarding covered defense information, and the prohibition of certain telecommunications equipment. Payment and invoicing must be processed electronically through the Wide Area WorkFlow system. Inspection and acceptance will occur at the destination, and the government requires a complete data package for any alternate part offers.

DLA WEAPONS SUPPORT LAND SUPPLIER OPNS VEHICLE SPT

POSTED

DEADLINE

More opportunities from Department Of Defense → Defense Logistics Agency

Same awarding agency

Supply of Enamel (NSN 8010-00-297-0554)This subcontract involves the supply of 5,000 gallons of enamel paint to prime contractors supporting Defense Logistics Agency Troop Support contracts. The material must strictly adhere to NSN 8010002970554 and UFGS-09900 Division 09 specifications, while remaining compliant with the DLA Master List of Technical and Quality Requirements. Delivery is designated as FOB Destination, with the place of performance located at Hunter AAF. The contractor is responsible for ensuring all packaging and labeling meet MIL-STD-129 and MIL-STD-2073-1E standards, specifically including the provision of lot and batch numbers. This procurement falls under NAICS code 325510 and is managed by the Department of Defense. The response deadline for this requirement is November 3, 2026.

Paint and Coating Manufacturing

POSTED

DEADLINE

Mold Release Agent Supplier (NSN 8030-01-233-1265)This subcontract involves the supply of a specific mold release agent, identified by NSN 8030-01-233-1265, to support prime contractors fulfilling Defense Logistics Agency requirements. The supplier must provide one 5-gallon can delivered FOB Destination to Illinois and US APO AE. To ensure product integrity, the agent must maintain a 12-month shelf life and be stored at temperatures between 60 and 80 degrees Fahrenheit. The contractor is required to adhere to strict regulatory and military standards, including compliance with the Buy American Act, the Berry Amendment, and 29 CFR 1910.1200. Additionally, all shipments must be packaged and marked in accordance with MIL-STD-2073-1E and MIL-STD-129. This procurement falls under NAICS code 325998 and is managed through the Department of Defense.

All Other Miscellaneous Chemical Product and Preparation Manufacturing

POSTED

DEADLINE

Supply of Refractory Castable Mix (NSN 9350015694317)This subcontract involves the supply of refractory castable mix to prime contractors supporting Defense Logistics Agency contracts for the USS George H W Bush and USS Abraham Lincoln. The provider is responsible for manufacturing or sourcing material that meets NSN 9350015694317, with strict requirements for packaging according to MIL-STD-2073-1E and marking per MIL-STD-129. The agreement mandates full compliance with the Buy American Act and the Hazard Communication Standard. The scope of work requires the delivery of two units of castable mix on a FOB Destination basis. This procurement falls under NAICS code 327120 and is managed through the Department of Defense. Interested parties must adhere to the response deadline of November 9, 2026.

Clay Building Material and Refractories Manufacturing

POSTED

DEADLINE

Supply of Incandescent Lamps (NSN 6240-01-563-9037)This subcontract through the Defense Logistics Agency involves the supply of 220 specialized incandescent lamps, specifically part number M6363/9-2 under NSN 6240-01-563-9037. The contractor is responsible for manufacturing or sourcing lamps that strictly adhere to MIL-DTL-6363J Revision J and MIL-DTL-6363/9A Revision A standards. All deliverables must meet rigorous quality assurance protocols per MIL-STD-1916 or ASQ H1331, with marking requirements following MIL-STD-129 and packaging compliant with RP001 and ASTM D3951. The project is subject to strict regulatory requirements, including mandatory compliance with the Berry Amendment and the Buy American Act. Performance for this contract is centered in Phoenix, Arizona, under NAICS code 334519. Interested parties must submit responses by November 9, 2026, to support prime contractors on DLA Troop Support projects.

Other Measuring and Controlling Device Manufacturing

POSTED

DEADLINE

FOB Destination Delivery Services (Patuxent River, MD)This subcontract involves the secure transport and delivery of specialized vehicular tires for prime contractors supporting Defense Logistics Agency supply contracts. The services are dedicated to the Naval Air Warfare Center Air Division, with all deliveries destined for a military installation in Patuxent River, Maryland. All shipments must be delivered FOB Destination within 20 days of receiving an order. To ensure successful execution, the contractor must provide drivers who possess the necessary valid identification and security clearances required for base access. This requirement falls under NAICS code 484220, with a response deadline set for November 9, 2026.

Specialized Freight (except Used Goods) Trucking, Local

POSTED

DEADLINE

Supply of Specialized Pneumatic Vehicular Tire (NSN 2610016070189)This subcontract involves the supply of specialized pneumatic vehicular tires, specifically NSN 2610016070189, for prime contractors working under Defense Logistics Agency contracts. The selected provider must manufacture or source tires that strictly adhere to MIL-DTL-4 specifications, ensuring a total non-extendable shelf life of 72 months. All items must be packaged and marked in accordance with MIL-STD-2073-1E and MIL-STD-129, with final delivery completed FOB Destination to Patuxent River. Compliance requirements include strict adherence to the Berry Amendment and a total prohibition on the use of Class I ozone-depleting chemicals. The opportunity is categorized under NAICS code 326211 and is managed by the Department of Defense. Interested parties must submit their responses by November 9, 2026.

Tire Manufacturing (except Retreading)

POSTED

DEADLINE

Compressed Gas Regulator SupplierThis subcontract opportunity with the Defense Logistics Agency requires the procurement or manufacture of one Compressed Gas Regulator matching NSN 4820010239625. The selected supplier must ensure that the unit is packaged in accordance with ASTM D3951 and the DLA Master List of Technical and Quality Requirements. Eligible bidders must possess a valid UEI and CAGE code to participate. The solicitation was posted on October 28, 2026, and requires a response by November 9, 2026. This requirement falls under NAICS code 423830.

Industrial Machinery and Equipment Merchant Wholesalers

POSTED

DEADLINE

Fluorescent Lamp SupplierThis subcontract opportunity with the Defense Logistics Agency under the Department of Defense seeks a supplier to provide fluorescent lamps for prime contractors. The required items must conform to NSN/FSC 015232050/6240 and be delivered to Phoenix, Arizona. The supplier is responsible for ensuring all hazardous material unit containers are labeled according to Hazard Communication Standard 29 CFR 1910.1200 and that all shipments comply with MIL-STD-129 marking standards for storage and transport. The solicitation was posted on October 28, 2026, with a response deadline of November 9, 2026, falling under NAICS code 423610.

Electrical Apparatus and Equipment, Wiring Supplies, and Related Equipment Merchant Wholesalers

POSTED

DEADLINE

Supply of Fluid Pressure Regulating ValvesThis subcontract involves the supply of two fluid pressure regulating valves for prime contractors supporting the Defense Logistics Agency. The specific requirement is for NSN 4820002856125, corresponding to Watts Regulator Co part number R-119-02C. All items must be delivered FOB Origin and must adhere to strict packaging and marking standards, specifically ASTM D3951 for packaging and MIL-STD-129 for shipment marking. The procurement falls under NAICS code 332912 and is managed through the Department of Defense. Interested parties must note the response deadline of November 9, 2026, to ensure compliance with the solicitation timeline established by the agency.

Fluid Power Valve and Hose Fitting Manufacturing

POSTED

DEADLINE

Manufacturer of Specialized Metal Bar (P/N 13056447)This subcontract involves the fabrication and supply of specialized metal bars, specifically part number 13056447, to support prime contractors fulfilling Defense Logistics Agency Troop Support contracts. The manufacturing process must strictly avoid additive manufacturing and adhere to several regulatory standards, including the Buy American Act, the Berry Amendment, MIL-STD-2073-1E, and MIL-STD-129. Finished products are to be delivered on an FOB Origin basis. To be eligible, providers must maintain ISO 9001:2015 certification and CMMC Level 2 certification verified by a C3PAO. Additionally, contractors must hold ITAR and EAR export control certifications. This opportunity falls under NAICS code 332710 and is managed through the Department of Defense.

POSTED

DEADLINE

Supply of Identification Markers

All Other Miscellaneous Manufacturing

POSTED

DEADLINE

Industrial Safety Lanyard SupplierThis subcontract involves the supply of an industrial safety lanyard for prime contractors under Defense Logistics Agency Troop Support contracts. The required product must match NSN 4240015516594 and adhere to specifications set by D B Industries or Carbis Ladders Division. All items must be packaged according to ASTM D3951 and marked in compliance with MIL-STD-129, while the supplier must ensure full adherence to the Balance of Payments Program and Buy American requirements. The contract specifies the delivery of one industrial safety lanyard FOB Destination to the USS Anchorage LPD 23. Managed under NAICS code 339999, the procurement process includes a response deadline of November 9, 2026.

All Other Miscellaneous Manufacturing

POSTED

DEADLINE

Earlier notices in this NAICS code

Posted before this notice, open and closed

SEAL, AIR, STATIONARY

Solicitation # SPE7L126F0516

Defense Logistics Agency

POSTED

DEADLINE

SEALING COMPOUND

Solicitation # SPE8ES26F43PM

Defense Logistics Agency

POSTED

DEADLINE

SEALING COMPOUND

Solicitation # SPE8ES-26-F-43PR

Defense Logistics Agency

POSTED

DEADLINE

SEALING COMPOUND

Solicitation # SPE8ES26F43QU

Defense Logistics Agency

POSTED

DEADLINE

Solicitation # SPE4A726PC674

Defense Logistics Agency

POSTED

DEADLINE

PACKING, PREFORMED

Solicitation # SPE7M1-26-V-0042

Defense Logistics Agency

POSTED

DEADLINE

Solicitation # SPE7L3-26-T-049S

Defense Logistics Agency

POSTED

DEADLINE

Solicitation # SPE7M0-25-T-4428

Defense Logistics Agency

POSTED

DEADLINE

Solicitation # SPE7L1-26-V-059X

Defense Logistics Agency

POSTED

DEADLINE

SEALING COMPOUND

Solicitation # SPE8ES26F43PA

Defense Logistics Agency

POSTED

DEADLINE

SEALING COMPOUND

Solicitation # SPE8ES26F43LU

Defense Logistics Agency

POSTED

DEADLINE

Solicitation # SPE7L3-26-T-062E

Defense Logistics Agency

POSTED

DEADLINE

Ready to Pursue This Opportunity?

Get AI-powered intelligence on this solicitation and the ones like it

Every page of the solicitation package shredded into a compliance breakdown

AI-powered matching based on your capabilities and past performance

Competitor and incumbent history on the requirement

Automated alerts on amendments, Q&A deadlines, and award

Join 750+ contractors already using CLEATUS