Panasonic EY9HX405E 12-Volt / 14.4-Volt / 15.6-Volt 1/2-Inch Keyless Chuck Panasonic Drills Fits on most cordless drills, threads onto 3/8" spindel Closes tight to grip as small as 1/32" round shanks Tightley grips round or hex shanks to 1/2" Small diameter compact design Includes a reverse threaded set screw