Designed for high precision CNC machine or heavy duty bench machine. Mounted with morse taper No. 4 shank for convenient quick change in operation. One set of solid steel internal jaws, one set of solid steel external jaws, and chuck wrench are also included in the package. Body is made of high quality semi steel. All pinions and jaws are harden to Rc 60-62. Please note the body of the chuck is mounted to the MT4 chuck plate which is an non-rotating piece.