Features 【Material】These spring collets set are made of high quality 65 million spring steel for CNC grinding turning tool and working machine. There are a total of 15 collets of different sizes in the set, which can easily meet your needs. 【With Label】Each collet is well packed in separate protective containers with label so you can easily distinguish them. Collet must be placed in a Collet treat nut before inserting into Collet Chuck. 【Strong and Robust】The spring switch is made of high quality spring steel, they are stable in performance. Fine workmanship, good elasticity, high precision. 【Specifications】Range: 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6. 5mm, 7mm, 1/8", 1/4"; Height: 18mm/0.7""; OD: 10mm/0.39""; Leakage tolerance: <0.008 mm. 【High Precision】Spring colet chuck provides the highest gripping force for better accuracy. Suitable for drilling, tapping, engraving, CNC, spindle machines and other processing. Description:These spring collets are made of high quality 65Mn spring steel for CNC milling lathe tool and work-holding engraving machine. There are total 15 collets of various sizes in on set which can basic meet your need. Each collet is well packed in separate protective container with label so you can easily distinguish them. Collet must be placed into collet chuck nut before inserting into collet chuck. Features:Made of high quality spring steel, they are stable in performance.Fine workmanship, good elasticity, high precision. Collet must be placed into collet chuck nut before inserting into collet chuck.Each collet is well packed in separate protective container with label.For CNC milling lathe tool and work-holding engraving machine. Specifications:Material: 65Mn spring steelModel: ER11Range: 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 1/8" ,1/4" Height: 18mm / 0.7" OD: 10mm / 0.39"Run-Out Tolerance: &lt;0.015mmWeight: 127g(approx.) Package Includes:1 Set(15pcs) x Collets Note: 1. Please allow 1-2mm error due to manual measurement. Thanks for your understanding. 2. Monitors are not calibrated same, item color displayed in photos may be showing slightly different from the real object. Please take the real one as standard. Package List