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