The Breakthrough Clean Technologies Armorers Wrench is the ultimate tool for your AR15/M4. Constructed out of durable titanium-plated stainless steel and includes a standard size muzzle device wrench. Easily installs and removes receiver extensions and castle nuts functioning with both Mil-Spec and Pin-Style Barrel Nuts. Compatible with Socket/Torque wrench and comes with a bonus Butt Stock Screwdriver.