The Makita DHR171Z is a 17mm cordless rotary hammer powered by 18V LXT Li-ion battery. It has a compact and lightweight design that includes vibration absorbing housing and an LED job light. With both forward / reverse rotation, the DHR171Z also features 2-mode operation, rotary only and rotary hammer. The unit also offers variable speed control by trigger as well as constant speed control for more efficient use. For easy operation, there is a one touch, sliding chuck for simple bit installation and removal. Other features include a brushless motor and an electric brake.