LinaLife is committed to providing each customer with the highest standard of customer Durable Material: The chuck of the milling cutter chuck is made of carbon steel, which has good flexibility and stable performance. Three Types of Chucks: Includes 6 engraving machine chucks, a total of three sizes, the chuck size includes 8mm,6.35mm, 6mm (0.31 inch, 0.25 inch, 0.24 inch), each size has two. Practical and Efficient: The high-precision woodworking milling cutter chuck can be well combined with your engraving machine, clamp the engraving machine tightly and stably to improve work efficiency. Application: It is suitable for the installation and modification of engraving machines, wood milling, trimming engraving machines, mol d manufacturing, milling cutters and wood milling engraving heads, increasing the use range of fixed engraving heads. Please Note: 1/4 (6.35mm) holes are mainly used in Europe and America, 6mm holes and 8mm holes are mainly used in Russia, Germany and other Middle East countries. Guarantees: LinaLife guarantees all buyers 100% satisfaction. 100% Satisfaction Guarantee for risk-free shopping.60 days money back guarantee for any reason If you have any problems about our products, please feel free to contact us. We will try our best to help you with your problems.