The next-generation PMAG 40 GEN M3 is a 40-round 5.56×45 NATO (.223 Remington) polymer magazine for AR15/M4 compatible weapons. Along with an expanded feature set and greater compatibility, it incorporates new material technology and manufacturing processes for enhanced strength, durability, and reliability that 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.