Maximum bit diameter 14". Input power 2400 w, 115 volts. The large rental core drill is a complete core drilling system for a variety of drilling applications. The system drills reinforced concrete, bricks, and other building material up to 14" in diameter (we rent up to a 10 inch diameter bit). The stand is tilt able for angle drilling, and features a convenient carry handle. Two-speed carriage gear box lits you choose crank speed for optimal performance, depending on application. Water cooled 3 speed gearbox for optimal drilling performance. Requires water, garden hose hook-up.