Brownells AR-15 5.56x45 NATO 20 Round Rifle Magazine Gray. The original 20 round profile is retained with improved geometry at the feed lips and at the bolt catch interface to ensure the most reliable magazine possible. New laser welded halves remove any potential for spot welds to deform magazine body ensuring a smooth ammo stack and exterior profile. Optimized for 5.56x45mm NATO / 223 Remington. Not intended for 300 Blackout. Note: These magazines feature a dry film lubricant on the exterior. This film will highlight scuffs and dings easily. This is normal for a USGI magazine finish. Specifications for Brownells AR-15 5.56x45 NATO 20 Round Rifle Magazine: Manufacturer: Brownells Color: Gray Magazine Body Material: Aluminum Magazine Capacity: 20 Round Caliber: 5.56x45mm NATO .223 Remington Gun Make: AR Platform Gun Model: AR-15 Quantity: 1 Features of Brownells AR-15 5.56x45 NATO 20 Round Rifle Magazine Stamped aluminum two half construction Laser welded seems Matte gray anodizing Dry film application to ensure smooth operation Re-profiled feed lips for improved performance Black follower (just like the original 20 round mags) Easy to remove floorplate Package Contents: Brownells AR-15 5.56x45 NATO 20 Round Rifle Magazine What firearm models does the manufacturer say Brownells AR-15 5.56x45 NATO 20 Round Rifle Magazine is compatible with? The manufacturer says that Brownells AR-15 5.56x45 NATO 20 Round Rifle Magazine is compatible with AR-15Brownells 430110983-20RD: AR-15 5.56x45 NATO 20 Round Rifle Magazine Gray