1、PRACTICAL DESIGN: OZ chuck has a full length slit, allowing the chuck to fold evenly to provide a concentric and full 360 degree clamping surface. 2、DURABLE MATERIAL: The spring collet is made of premium spring steel material, which is resistant to high temperature, corrosion, and stable performance 3、FINE WORKMANSHIP: After heat treatment and cold drawing hardening, the strength is relatively high, and the collet has a certain degree of flexibility and plasticity. 4、WIDELY USED: For clamping tools such as milling, drilling, tapping, engraving, CNC, spindle machines, etc. Widely used in machining centers, ordinary milling machines, CNC milling machines, engraving machines, high speed machines, and other processing. 5、4PCS: There are 4 pieces collets in the package in different sizes that use them respectively to meet your different needs.