The hybrid steel and polymer design of this drum magazine gives the best of both worlds with overmolded steel feed lips and mag catch combined into a high impact polymer housing. The patent-pending design brings belt feed reliability and performance to drum magazines. This drum magazine fits all SR-25/LR-308 pattern compatible .308/7.62mm NATO AR-type rifles. It has a 50-round capacity and a black finish.ProMag magazines are designed utilizing modern precision injection molding of Mil-Spec polymer compounds. Every ProMag magazine is backed by a lifetime guarantee against manufacturer's defects. Features: Over molded stamped steel feed lips and magazine catch Magazine body constructed of a proprietary DuPont Zytel based polymer Injection molded magazine follower Heat treated stainless steel magazine spring Made in USA