1″ impact wrench# 5 spline drive anvil1600 foot lbs. of torque 6″ extended anvil for extra access 3 forward and 3 reverse power settings with d side handle for ease of use this 1 in.; drive impact wrench features a #5 spline drive. it has a 6-inch extended anvil for extra access and 1600 ft. lbs. of ultimate torque. there are 3 forward and 3 reverse power settings. this tool is a workhorse – it is very powerful and durable.