A favorite among civilian and professional shooters alike, the ProMag® AR-15 5.56mm 40-Round Steel-Lined Magazine with Roller Follower is an affordable aftermarket magazine, featuring a steel-lined Technopolymer body, designed to deliver exceptional durability, while over-molded stamped steel feed lips offer a snug, wobble-free fit for reliable operation. A heat-treated, anti-fatigue, chrome silicone wire internal spring, coupled with the proprietary Roller follower, eliminates binding and delivers exceptionally smooth feeding operation for added reliability. Over-molded stamped steel feed lips offer a snug, wobble-free fit for reliable operation. Plus, this American-made magazine is backed by ProMag's legendary lifetime warranty for lasting service you can truly depend on when it matters most. Order today! Made in USA.