It has controlled pressure to ensure a consistent surface finish and round cylinder shape. Operates with any electric drill. Adjustable stop collar permits quick selection of two range settings, from 2" to 4" and from 4" to 7". Furnished with 3" long 220 grit stones. Stone arms are easily compressed to eliminate cylinder scratches Controlled pressure assures positive, adjustable contact through full range. Operates with any electric drill. Adjustable stop collar permits quick selection of two range settings, from 2" to 4" and from 4" to 7". Stone arms are easily compressed to eliminate cylinder scratches. Skin-packed. Shipping wt. 1 lb. 4 oz.