A 13mm or 16mm grip can be used for grabbing small turnings or pen mandrels on the headstock or a drill bit in the tailstock with MT1 or MT2 adaptor.

Also could be used for drill press.

K13+MT1: 13MM HEAVY DUTY KEY CHUCK + JT6-MT1 ADAPTOR

K13+MT2: 13MM HEAVY DUTY KEY CHUCK + JT6-MT2 ADAPTOR

K16+MT1: 16MM HEAVY DUTY KEY CHUCK + JT6-MT1 ADAPTOR

K16+MT2: 16MM HEAVY DUTY KEY CHUCK + JT6-MT2 ADAPTOR