Bosch 1-9/16-Inch SDS-Max Combination Rotary Hammer RH540M CONVENIENT: The Bosch RH540M Combo Rotary Hammer features the SDS-max Bit System for tool-free bit changes with automatic bit locking, dust protection and maximum impact energy transfer rate. POWER: This rotary hammer provides the best in class impact energy of 6.1 ft.-lbs. Weighing only, 15.2 lbs., the RH540M provides maximum productivity in all day drilling and chiseling applications. VERSATILE: The RH540M features a combination dual mode selector knob to allow users to select between hammer drilling, chiseling only and the Vario-Lock function. EFFICIENT: With Varo-Lock Positioning, the rotary hammer rotates and locks chisel into 12 different positions to optimize working angle. The tool also comes complete with service minder brushes to notify users when maintenance is needed. VARIABLE SPEED: The variable speed dial allows for controlled drilling and chiseling applications. The motor is rated at 170 to 340 RPM in rotary mode and 1,200 to 2,750 BPM in hammer mode, which will easily reduce concrete to dust.