Spike's Tactical is committed to providing customers with access to the same high-grade, professional-quality tools that we manufacture for our own use in the armory. The AR-15 castle nut wrench is precision-engineered from chromoly-steel, featuring a black phosphate coating to ensure enhanced durability and superior corrosion resistance The device is engineered to accommodate a 3/8 inches drive for torque wrenches and features cutouts specifically designed to fit standard AR-15 carbine buffer tube castle nuts