The Bosch HTH182-B25 18V High-Torque Impact Wrench Kit includes an industrial-duty impact wrench with a 7/16 In. hex chuck. It was engineered for concrete contractors, auto pros, carpenters and other pros who spend a great deal of time fastening high-torque nuts and anchors, such as lag screws or lug nuts. It provides professional cordless torque, delivering up to 500 Ft.-Lbs. The cordless tool provides a 7/16 In. hex quick-change anvil for fast changing of bits. The all-metal motor generates 0-2,100 ipm and 0-1,900 rpm. This impact wrench has a spring-loaded hammer-and-anvil system that controls torque reaction to allow for easier impact-driving power. The kit includes two next-gen CORE18V 4.0 Ah compact batteries. Each keeps the power and runtime, while losing the weight, with 21700 cell technology. The CORE18V matches the power of the original two-layer 4.0 Ah battery with half the number of cells. It features the CoolPack 2.0 heat-management system.