Magpul Industries Magazine, PMAG 30 AR/M4 M3 With Window, 223 Remington/556NATO, 30 Rounds, Fits AR Rifles, Medium Coyote Tan MAG556-MCT The next-generation PMAG 30 AR/M4 GEN M3 Window is a 30-round 5.56x45 NATO (.223 Remington) polymer magazine for AR15/M4 compatible weapons that features transparent windows to allow rapid visual identification of approximate number of rounds remaining. Along with expanded feature set and compatibility" the GEN M3 Window incorporates new material technology and manufacturing processes for enhanced strength" durability" and reliability to exceed rigorous military performance specifications. While the GEN M3 is optimized for Colt-spec AR15/M4 platforms" modified internal and external geometry also permits operation with a range of additional weapons such as the HK 416/MR556A1/M27 IAR" British SA-80" FN SCAR MK 16/16S" and others.