Cordless Impact Wrench uses batteries to generate power. The motor builds up energy using rotation and then pushes it into an anvil that is located at the end of the tool. This creates an enormous amount of torque that is more than can be produced by any human. Cordless Impact Wrench is used for tightening and loosening bolts, lug nuts and rusted fasteners. It provides a very high rotational torque that regular drills are simple and not capable of and delivers high torque output with minimal exertion by the user.