ITEM NAME:ER11 CNC Collet Chucks Tool Bits Holder 1/8 Inch (3.175mm) 4mm 6mm Z3Z9 ER11 CNC Collet Chucks Tool Bits Holder 1/8 Inch (3.175mm) 4mm 6mm Z3Z9 Hardness: 44-48HRC 100% Brand New and High Quality. Type: CNC milling Lathe Tool Color: silver Material: spring steel Specification: 1/8 4mm 6mm Package Contents: 3 x CNC ER11