The Duramag® AR-15 6.8 Grendel 5-Round Stainless Steel Magazine features a durable 410 stainless steel body with a proprietary Teflon coating to deliver smooth performance, while Post & Hole™ robotically welded construction offers exceptional strength and durability for lasting performance. The EverFlex™ anti-fatigue steel spring, coupled with an Advanced Geometry Follower™ ensures reliable feeding performance. Better yet, this magazine is crack-, swell-, and crush-proof for superior durability.