The Pro Mag drum magazine is specially designed to work seamlessly with your AR-15 that uses Glock style mags. This product is expertly constructed with DuPont\'s sturdy and reliable Zytel polymer. Additionally, it features an injection-molded mag follower and a mag spring composed of chrome silicone wire for advanced performance. Proudly made in the USA, this gun accessory ensures excellent durability and effectiveness, promising to be a valuable addition to your equipment.