The Thexton Rapid Core Remover, No. 819, attaches directly to a drill, or it can be used by hand. The 4-in/lb clutch prevents over-tightening. The tool fits most common size Schrader valves and standard bore tire valves. To use, remove the valve cap from tire; insert the tool into the valve stem and hand loosen the first turn; insert the tool into the correct “power bit” drill adapter; ensure the drill is set to reverse; insert the tool into the valve stem and depress the button on the drill to remove valve core; and install the new valve core by hand until an audible click is heard.