The Phase 5 AR-15/308 Oversized Magazine Release is a drop-in two-piece assembly which replaces the standard mil-spec magazine release button. With easy installation that requires absolutely no gunsmithing, the Phase 5 AR-15/308 Oversized Magazine Release is a breeze to install, Larger contact surface than the standard magazine release button Ergonomic pocket on surface paddle for your finger Materials: 6061-T6 billet aluminum Compatible with Extended Bolt Releases The Phase 5 AR-15/308 Oversized Magazine Release will make mag drops faster and easier. Mfg: Phase 5 Tactical