SDS-max® bit system provides tool-free bit changes with automatic bit locking, dust protection and maximum impact energy transfer rate. Combination dual mode selector knob allows the tool to be switched between rotary hammer mode or hammer only mode. Integral clutch disengages torque transmission if the bit gets into a bind situation. Vario-Lock™ positioning feature rotates and locks chisel into 12 different positions to optimize working angle. 360° Auxiliary handle provides a wide range of movement along with operator comfort.