Specialized, precise-fitment armorer's crowfoot wrench, fits A 1/2" receiver torque wrench head - Purposefully designed, 2-sided to fit both 20-hole and 4-hole free-float barrel nuts - Titanium coated stainless steel to confidently apply desired torque while minimizing marring on gun parts - Tight tolerances for solid grip and no-slip tool control. Mfg: Real Avid