The Hougen Models HMD915 & HMD916 also offer 115V and 230V power choices. These big brutes have the power to drill up to 3-1/16" holes thru 3" thick material. Both models feature high and low speed ranges to deliver extra torque when required. Optional gearing is available for up to seven speeds. Both models use the "42/43,000-Series" Rotabroach Cutters, or with an arbor adapter they can use "12,000-Series" Cutters. They have all Hougen safety features built in including impactor points for improved torsional stability.