Milwaukee® No. 404 Woodruff Key is designed for electric drill, grinder, 1/2" electric drill, 1/2" reversing compact drill, cordless drill/ driver, cordless 18 V keyless 1/2" D-handle drill, dymodrill, drill press, two speed hole hawq drill, hammer drill, "D" hammer drill, single speed hole hawg drill, positive drive screwdriver, 8" tuck point grinder, 3/4" electric drill and electric drill/driver.