Bolton MT3 End mill chuck with 16 piece collet set Quick Change Collet Chuck Includes: 1/8",3/16",1/4",5/16" 3/8", /16", 1/2", 9/16", 5/8", 11/16", 3/4", 13/16", 7/8", 15/16" 1" Spanner wrench and moulded plastic case. MT3 Spindle Taper