PMAGA(R) AR/M4 GEN M3(TM) 5.56X45MM NATO RIFLE MAGAZINES FOR AR-15 The next-generation PMAG GEN M3 is a true 10 or 20 round polymer magazine for AR15/M4 compatible weapons chambered in 5.56x45 NATO / .223 Remington. Along with an expanded feature set and compatibility, the GEN M3 incorporates new material technology and manufacturing processes for enhanced strength, durability, and reliability. The PMAG provides next-generation performance. The PMAG GEN M3 features a long-life stainless steel spring, four-way anti-tilt follower for reliable feeding, and an easy to disassemble. Aggressive front and rear texture give positive control of the GEN M3 in all en Mfg: Magpul