The Duramag® AR-15 6.8mm SPC 28-Round Stainless Steel Magazine features a robotically welded 410 stainless steel body with a proprietary Teflon T-360™ finish for superior durability in adverse conditions. The LipLock feed lip design keeps rounds secured and in proper alignment for jam-free reliability, and the EverFlex™ anti-fatigue steel spring and the Advanced Geometry Follower™ protect against binding and deliver smooth feeding performance you can count on.