Router collet extension for 8mm shank bits, need to tighten with wrench to prevent bit from falling out. Made of heavy duty steel for long life life, convenient to use. Eliminate the dangerous temptation to pull the shank off the collet, extend the bit to provide the full depth of cut. Make you more efficient to process products, suitable for wood cutting, milling, engraving. Package content : 1 x 8mm Rod Collet Extension. Product Collet Extension Feature:< /p> This clamp extension is made of industrial grade material, high precision, solid and sturdy for long service life. This router collet chuck provides the extra depth of cut needed for many routing tasks. Easy to use, better to control, it will improve the efficiency of your work. Use it to achieve full depth of cut when machining dovetail flutes, ideal for your woodworking. Extension Specifications Clamp: Material: Hard Alloy Black Color Stem diameter: 8mm Holding diameter: 8mm Overall length: 87mm Package Included: 1 x Router Clamp Extension Note: 1. The speed reaches 20000 RMP 2. For the higher hardness material, please use 1/2 handle 3. Cannot be used for iron products, be careful if there are nails in the board or the like 4. Please take protective measures when using