STEEL SHANKSThis set includes a 5-inch rubber roller attachment that has two 8mm steel shanks to fit your drill and the included 20mm, 30mm, 35mm, and 45mm attachable rubber suction cups that make fitting and seating various valve sizes easy. | EASY TO USEUse with your existing electric drill and automotive valve grinding compound (not included) to correct surface irregularities and to remove sub-surface damage on your new valves when working on a top-bottom rebuild. | INCREASED CONTROL & PRODUCTIVITYThe attachment provides increased control and productivity for your projects. Working speed min is 1000 RPMs. Working speed max is 1250 RPMs. |