A 4 jaw midi sized geared scroll chuck, for simple one handed operation. The serrated jaws, fitted as standard, can grip the workpiece both internally or externally & a range of optional jaws are also available. the chuck fits directly onto 1" x 8tpi threads or 3/4" x 16tpi using the insert. Supplied in a plastic storage case (with space for optional jaws), wood screw, t-bar & 3/4" x 16tpi insert. specifications: mounting thread: 1" x 8tpi or 3/4" x 16tpi. chuck body diameter: 63mm. standard jaw expands: from 34mm to 60mm. standard jaw contracts: from 48mm to 22mm. weight: 920g. rating: diy.