The most powerful rotary hammer from bosch the bosch gbh12 52d hammer drill provides top performance when drilling and chiselling thanks to 1700w motor and 19 joules of single impact energy whilst the speed controller gives optimum adjustment to suit the application user benefit top performance when drilling and chiselling thanks to 1700 watt motor and 19 joules of single impact energy automatic switch lock for the best convenience in continuous chiselling applications long lifetime due to robus