Specifications:<br> Material: Durable steel<br> Shank Diameter: 1/4 Inch/ 6.35mm<br> Hold Diameter: 1/4 Inch / 6.35mm<br> ER20 Spring Collet: 6.35mm/ 1/4 inch<br> ER20 Spring Collet: 12.7mm/ 1/2 inch<br> Wrench Spanner: ER20 M Type; High Carbon Steel; Anti-slip handle Design<br><br> Package Included:<br> 1 * Router Collet Extension<br> 1 * 1/2 inch ER20<br> 1 * 1/4 inch ER20<br> 1 * ER20 M Type Collet Chuck Wrench Spanner<br><br> Accept Shank Size: 1/4" & 1/2" Shank<br> Extend Length: 2-1/4 inch<br> For CNC Engraving Machine & Milling Lathe Tool Holder.<br><br> Features:<br> 1. High precision, stable performance. Extend your bowl router bit to provide the full depth of cut.<br> 2. This chuck collet is made of industry grade material, with high precision, sturdiness and durability, and long service life.<br> 3. Collet wrench anti-slip handle design for manipulating ease.<br> 4. Widely application combination set, it will improve your work efficiency.