For with Vac-U-Rig and Dymorig diamond core rigs to drill holes into reinforced concrete 20 amp motor has 4.8 peak horsepower 300 or 600 RPM operating speed Replaceable shear pin protects gears and motor against overload Handles core bits from 4in. to 14in. in diameter Built-in water swivel Includes cord with 20 Amp twist-lock plug, adapter to receive standard water hose, water control valve, 6 extra hardened shear pins, and wrench Model 4079 U.S.A.