Features: * Brand new and high quality * Conveniently keep multiple chucks ready for use. Changing chucks on the fly can be difficult, and having a few spare chucks for different sizes can make tool changes easy. * High precision and high concentricity extend the service life of the spindle and reduce the drill bit breakage rate. * Material: alloy steel/quenched steel. Precision ground and hardened. Suitable for ER-type tool holders, tool bars, extension rod nut-fixed drill bits, boring tools and other tools. * All nuts have dynamic balancing holes to prevent wear and noise. Specification: Type: ER collet chuck nut Material: alloy steel Model: ER8-A, ER8-M, ER11-A, ER11-M, ER16-A, ER16-M, ER20-A, ER20-M, ER25 UM, ER32 UM, ER40 UM (optional) Color: as shown in the picture Application: CNC cutting tools, woodworking machinery, engraving machines Quantity: 1pcs Package Included: 1 x ER collet chuck nut Note: 1.The real color of the item may be slightly different from the pictures shown on website caused by many factors such as brightness of your monitor and light brightness. 2.Please allow slight manual measurement deviation for the data. Kairuite ER8-ER40 A/M/UM Collet Clamping Nuts For CNC Lathe Milling Router Bit Holder Easy to install and reliable to use. Solid and durable, long service life. Pls kindly check the decription before you order. Any other in need pls contact with us directly Brand new and high quality