Custom machined milling machine knee feed adapter socket with 1/2″ shank. Easy and inexpensive way to raise and lower Z axis on Bridgeport type and other milling machines (JET, ENCO, ACER, GRIZZLY ect) with a 1/2″power drill. This will save you time and your arm from having to crank the knee handle. The knee feed adapter fits most mills with 5/8″ diameter knee shaft. Socket adapter machined to .630″ I.D. 1.600″ deep with 9 splines. Heavy duty hardened steel with black finish. Please e-mail with questions.