The Magpul Armorer's Wrench – AR15/M4 is an American-made, solid steel tool with grip-enhancing phosphate finish that engages both stock and pin-style barrel nuts. Fits standard sized flash hiders. Installs and removes rifle receiver extensions and carbine castle nuts, and has extended teeth for use with ASAP plates. Includes two hammer faces.The Magpul Armorer's Wrench works with a 1/2" torque wrench, and relevant torque specifications are included on the tool for quick reference. Convenient Bottle Opener for refreshments after the build is complete (fits both Metric and SAE bottle caps).