This is the new standard for a professional armorers wrench. Smarter, stronger, ergonomic. It fits your hand and your gun precisely. The Real Avid Armorers Master Wrench features best-in-class strength, precision fitment and ergonomic intelligence. Wrenches seat squarely for a no-slip fit on stubborn barrel nuts, castle nuts, muzzle brakes, or fixed stock receiver extensions. Industry first torque wrench attachment location is optimally positioned to provide consistent torque for all nuts. As a bonus, interchangeable hammer heads make the Armorers Master Wrench a Master hammer as well! This is the right tool for the job and for you.