ASC Stainless Steel magazines are an improvement on a classic, with the highest levels of durability and increased longevity, simply the best in the industry! Our magazines are manufactured 100% start to finish in the USA using .020 gauge 410 Stainless Steel Alloy, heat treated for superior strength and lasting endurance. Our magazines are chemically treated for corrosion resistance [ref QQ-P-35] and coated with our proprietary finish, Marlube which is a wear-in not wear-off coating that burnishes into the surface providing self-lubricating properties. The interior dimensions of OAL 2.316" .002 are perfect for reloads.Features and Specifications:Manufacturer Number: 20-223-SS-BM-O-ASCASC AR-15 MagazineCaliber: .223 Remington, 5.56 NATOCapacity: 20 RoundsBody Material: .020 gauge 410 Stainless Steel AlloySpring Material: Chrome Silicon WireFollower Material: PolymerBaseplate Material: 300 series Stainless Steel AlloyFollower Color: OrangeHeat treated for strength and durabilityChemically treated for corrosion resistanceMil-Spec Anti-Tilt FollowersFinish: Black Marlube Finish, Matte Black Powder Coated Floor PlateFits:Standard AR-15 Platform Firearms