Malco Hole Cutters adjust for making 2 to 20 inch diameter holes in galvanized sheet metal. The large capacity model HC2 cuts a full 2 inch to 20 inch range while the more compact HC1 cuts a maximum 12 inch diameter. Both Hole Cutters install into a standard electric drill as small as 1/4". Malco Hole Cutters store easily in a tool box and feature lightweight aluminum frames and high speed bearings at the top and bottom of the drill shaft to assure perfect cutting balance and long cutting life.