1、STURDY AND STABLE: These spring collets are made of high carbon steel, which are sturdy and long lasting, very stable in performance. 2、4 JAW: These CNC lathe collets are constructed with four jaws, providing excellent contact and strong grip, ensuring secure fixation. 3、WIDE USAGE: These collet chucks are suitable for various grinding machines to clamp grinding heads, suitable for repairing and grinding tires, and compatible with most rotating tools. 4、MULTI PURPOSE: These collets can be widely used in machining centers, ordinary grinding machines, CNC grinding machines, engraving machines, high speed machines, and other processing. 5、FINE MADE: These collets are very practical tools for CNC lathes, which are made with fine workmanship, standard and professional. Item Type: Collet Set Material: High Carbon Steel Specification: d=12x9, d=11x9, d=11.2x9, d=10x8 4 x Collet 4 x Storage Cylinder