Bosch 11247 10 Amp 1-9/16-Inch Spline Combination Hammer 10-amp motor delivers 400 rpm and 3,000 bmp Constant response circuitry maintains speed under load and provides overload protection Combination dual mode selector, 2 modes of operation, rotary hammer and hammer only mode Vario-lock chuck allows for user positioning of chisel 360-degree auxiliary handle provides a wide range of movement for user comfort