Real Avid Armorer's Master Wrench - The ergonomic handle gives you the ability to apply serious torque needed to remove stubborn, crusted-on barrel or castle nuts without marring your firearm or stripping the nuts. The tool holds shape under pressure and has deep set sockets to grip your nuts and keep them gripped. Castle Nut WrenchFixed Steel Hammer HeadBrass Hammer HeadTorque Specs Laser Etched Behind Hammer HeadsMil Spec Barrel Nut WrenchRubber Hammer HeadNylon Hammer Head