Atoplee 1pcs 1/4 inch ER11 Spring Collet Set for CNC Engraving Machine & Milling Lathe Tool Material: 65Mn MODEL: ER11 1/4'' Length:17.7mm Precision:less than 0.012; Height:0.69'', Outside diameter: 0.45'' (11mm) Package Included: 1pcs CNC ER11 Collet