TEKNATOOL SUPERNOVA 2 CHUCK W/2" JAWS & WOODWORM SCREW (SUPERNOVA2) W/ 5/8" Shopsmith type insert Weight 5-1/2 lb Diameter of chuck is 3-7/8" Kit includes 5/8" Plainbore Shopsmith type adaptor insert (ISNS) One Handed tightening with incredible gripping power Accepts full range of Nova jaws