The Hexmag HX Series 2 features a superior Grip which is achieved with Hexmag's patented hexagonal surface pattern as well as the pronounced ribbing on the front and back of the magazine. This combination provides a comfortable and sturdy grip when completing magazine changes. The Hexmag Anti-Tilt Follower was engineered with equal length legs to prevent tilting forward or backwards keeping the ammo in a straight double stack. The High visibility, Hexmag Orange Follower allows for safer clearing of your rifle's chamber. A Heat Treated 17-7 PH Stainless Steel Spring, allows for long term magazine storage while fully loaded and stainless steel resists corrosion unlike music wire or silicon steel springs. Hexmag magazines feature a Fiber Reinforced Polymer Construction that is lighter than other leading AR-15 magazines making it a perfect option for competition shooters looking for weight savings. The HX magazine is designed for use with 5.56x45 NATO/.223 Remington, 300AAC Blackout approved, (both supersonic and subsonic .300AAC blackout ammo) .458 SOCOM and .50 Beowulf tested working by independent manufacturers. National Tactical Officers Association tested and approved. NTOA Hexmag utilizes the same size magazine body for all three capacity options. Hexmag developed a system that does not require the use of pins or limiters. Hexmag didn't take their 30-round magazine and alter it, they actually changed the internals to mimic a shorter 10 and 15-round magazine. The Hexmag True Riser system features a Patent Pending, fiber reinforced Riser that is engineered to bring the base of the spring up. A shortened, heat treated, stainless steel spring is then used to connect the riser and follower. This system mimics a shortened magazine but keeps the benefits and style of a standard size 30-round Hexmag magazine body. Hexmag's system as shipped cannot be converted back to 30-rounds. Hexmag does not sell parts to convert their magazines to 10, 15 or 30 rounds due to state restrictions. Features Superior Grip is provided by Hexagon Surface Patterns High visibility anti-tilt follower and Heat treated 17-7 PH stainless steel spring Compatible with Hexmag's Hex ID system True Riser Systems Limits shorter Mags from using any extra rounds30 rounders