The DeWalt DC821KA 1/2 Inch Heavy-Duty 18V Impact Wrench offers the ergonomics and control features of a compact impact wrench with its light weight, small size and comfortable handle set, as well as the constant-duty durability and runtime of larger wrenches. The DeWalt DC821KA 18V impact wrench has a high speed all-metal transmission that delivers 0-2,100 RPM for increased productivity. The DeWalt DC821KA has a DeWalt built; high power motor with replaceable brushes that delivers maximum performance, durability and serviceability. The DeWalt DC821KA has a variable speed reversing switch which provides control for both setting and removing fasteners and an electric brake that prevents completely backing out and losing fasteners.