KEYED CHUCK OPTIONS: can be used as a replacement or as an additional option GENERAL PURPOSE: designed to be used with a drill with a forward and reverse function CAPACITY UP TO: 13mm, perfect for most basic drilling tasks CHUCK AND DRILL INTERFACE: 1/2" x 20 UNF KIT INCLUDES: a chuck key to tighten chuck to drill bits DIAMETER: 13mm FITS: &D, AEG, Bosch, Elu, Fein, Hitachi, Kress, Makita, Metabo, Panasonic, Skill, Wolf.