Bosch 11318EVS 1-9/16-Inch 11-Amp SDS-Max Demolition Hammer SDS-Max bit system offers tool-free bit changes with automatic bit locking, dust protection and maximum-impact energy transfer rate Auto-Max variable-speed dial is designed to automatically ensure the maximum speed and power Constant Response circuitry provides soft-start and maintains constant speed under load Service Minder light indicates when preventative maintenance is required Vario-Lock positioning rotates and locks chisel into 12 different positions