This crows foot AR-15 barrel nut wrench tool is constructed from drop forged steel with 6 pins for removal and installation of your USGI barrel nut. This barrel nut wrench can be used with a 3/8 or a 1/2-driven torque wrench for proper torque specifications. The barrel nut wrench is specifically designed for the AR15, M16, and M4 USGI Mil-spec standard barrel nut built to military specifications with a 20-hole pattern. Limited one year warranty.