The Okay Industries Surefeed 30RD Magazine is a USGI type American made battle tested and proven magazine. This tough Magazines fits and functions in all AR-15/M-16 style rifles and carbines that meet military specifications. Formally only available to the U.S Government customers, this Surefeed mag is made of high-quality lightweight aluminum. The Okay Industires Surefeed 30RD Magazine is has Mil-spec Dry Film Lubricant finish for added strength and durability. On the inside, this great mag uses a self-lubricating 4-way foliage green anti-tilt follower made of non-hydroscopic resin. The MILSPEC stainless-steel magazine spring keeps rounds properly aligned with the perfect tension.