Diameter range: 5/8 to 6-1/2 in.
Combination round/square shank can be used with a bit brace or hand drillMade of steel, including graduated beam for adjusting diameters from 5/8 in. to 6-1/2 in.Two independently adjustable blades cut inside and outside diameters at the same timeOnly safe to use with a handheld variable-speed drill running at less than 100 rpm