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 reliable crack resistance for lasting performance under stress. The EverFlex™ anti-fatigue steel spring works in tandem with the Advanced Geometry Follower™ to deliver reliable, jam-free feeding performance and consistent field performance. Better yet, this magazine is crack-, swell-, and crush-proof for superior durability in difficult, fast-action environments.