Features and Benefits:?Two speeds: 300 and 600 RPM?20 amp motor?Clutch protection protects gears and motor?Built-in water swivelDiamond coring motors are used with Vac-U-Rig? and mooring diamond core rigs to drill holes into reinforced concrete. This 20 amp model features 4.8 peak horsepower with a 300 RPM or 600 RPM operating speed. The 4004 has a clutch to protect gears and motor against overload. This unit will handle core bits from 4 in. to 14 in. in diameter.