Bosch 11221DVS 7/8-Inch SDS Rotary Hammer Integrated dust collection system - keeps work environment clean in critical areas SDS-plus bit system - tool-free bit changes with automatic bit locking, dust protection and maximum impact energy transfer rate Multi-function selector - 3 modes of operation, rotation only, rotary hammer and hammer only mode Variable-speed reversing trigger - for accurate bit starting, as well as removing fasteners or bound bits Constant ResponseTM Circuitry - - Provides soft-start - Maintains constant speed under load - Provides overload protection