The Bosch HTH181B 18V High-Torque Impact Wrench with Pin Detent is a heavy-duty impact wrench with pin detent system for tool-free socket installation. The wrench is engineered for fastening high-torque nuts and anchors. It delivers up to 500 Ft.-Lbs. of torque. Its spring-loaded hammer-and-anvil system moderates torque reaction to allow for consistent driving power and control, and the wrench is built with an all-metal motor that produces up to 2,100 ipm and up to 1,900 rpm. It offers a square drive 1/2 In. pin detent and true flat anvil design for convenient changing of sockets.