Description: Application Suitable for boring milling drilling tapping engraving CNC spindle machines and other processing. Premium Quality These spring collets are made of high-quality spring steel they are stable and practical in performance. Easy to Distinguish Each collet is well packed in a separate protective container with the label moreover each collect is marked with size so it’s easy to distinguish them. Specification: Model: ER20 Material: High Grade 1065 Carbon Steel Run-Out Tolerance: 0.015mm(0.0006 ) Size: 1/8 3/16 1/4 5/16 3/8 7/16 1/2 Packing List: 7 x ER20 Spring Collets