1、Firm Clamping: With high elasticity and strong clamping force, the stable spring collet ensures no vibration or loosening. 2、13Pcs in Pack: There are 13pcs chuck collet in the set, which enables a wide clamping range from 1mm to 7mm, very useful. 3、Broad Utility: Suitable for ER tool holder, extension rod nut, clamping drill, boring tool, carving tool, reamer and so on. 4、Advanced Work: Through exquisite workmanship, has good low temperature impact toughness and high accuracy, very durable. 5、Easy Storage: Each collet has its own storage box, adding more convenience to the carrying for daily use. 13 x Spring Collet13 x Storage Box Item Type: Spring ColletMaterial: Spring SteelClamping Range: Approx. 1 ~ 7mm / 0.04 ~ 0.28in (1mm / 0.04in, 1.5mm / 0.06in, 2mm / 0.08in, 2.5mm / 0.1in, 3mm / 0.12in, 3.5mm / 0.14in, 4mm / 0.16in, 4.5mm / 0.18in, 5mm / 0.2in, 5.5mm / 0.22in, 6mm / 0.24in, 6.5mm / 0.26in, 7mm / 0.28in)Tolerance: ± 0.01mmProduct Quantity: 13pcsScope of Application: Suitable for ER tool holders, tool holders, extension rod nuts, clamping drills, boring tools, carving tools, reamers.