FAB Def. Magazine well grip for AR15/ M16 /M4 type. Transform your existing magwell onto a fast action magwell and ergonomic grip. Mounts directly below the receivers front pivot pin and OVER the existing magazine well. Provides a large beveled opening for Super-Fast magazine changes. No Gunsmithing or modifications to the weapon needed. Easy installation – Simply tighten into place utilizing 3 set screws. Light weight - constructed of reinforced polymer composite