ITEM NAME:1pc 1/4" to 1/8" Quick Reducer Adapter Chuck Collet for Die Grinder Rotary Tool Product Description 1pc 1/4" to 1/8" Quick Reducer Adapter Chuck Collet for Die Grinder Rotary Tool Product Description 6mm-3mm chuck (1/4 -1/8) do not need to replace the chuck can easily put the 3mm grinding head in the 6mm grinding machine.Suitable for electric grinding machine rotary tools Specifications: Material:metal Color:black Outer diameter:6mm(1/4") Inner diameter:3mm(1/8") Toal length:20mm Conversions:1 mm= 0.039inch, 1 inch=25.4 mm Note: Please pay attention to the protection measures before using the tool Package include:1pc X Collet Chuck Notice: 1.Please allow 1-3cm error due to manual measurement,Please make sure you do not mind before you.Head in the 6mm grinding machine.Suitable for electric grinding machine rotary tools. 6mm-3mm chuck (1/4 -1/8) do not need to replace the chuck can easily put the 3mm grinding. We will try our best to reduce the risk of the custom duties.