Bosch 11536C-1 36-Volt BBS Litheon Compact Rotary Hammer
The 11536C uses an electronically commutated (brushless) motor – the first professional Bosch power tool driven by an EC Motor. Eliminating limitations in conventional motors, power is pulsed on and off electronically with semiconductor devices, thereby maintaining high torque and speed from the start.  The 11536C is optimized to give the best performance for the most common diameters, not the largest, making it great for smaller diameters and overhead drilling.  The speed and impact rate are also optimized to provide the best drilling rates.  Only with Bosch will you get the right combination of speed, power and vibration.