ProMag magazine bodies are constructed of polymer for strength. The springs are precision wound using heat-treated chrome silicon wire. Bases and followers are injection molded from polymers selected for their durability. The result is quality, consistency, durability and reliability. This 55-round drum magazine fits the FN 5.7X28MM AR style carbine. IT DOES NOT FIT FN Five-seveN USG 5.7x28mm pistol!!! The magazine body constructed of a proprietary DuPont Zytel™ based polymer, blue steel upper magazine tower, injection molded magazine follower. The magazine spring formed from heat treated stainless steel, and everything is made in the USA.

Specifications: Caliber: 5.7x28mm, Capacity: 55 Rounds, Body Material: Polymer, Color: Black

This is for one 55 round drum magazine for 5.7 caliber AR style carbines.