ITEM NAME:High-quality 6mm to 3.175mm 1/8" engraving bit cnc router adapter for collet@ Hn Material: Spring Steel Function: Engraving bit CNC router tool Adapter 6mm to 3.175mm Size: Diameter(Outer): 6mm, Diameter(Inner): 3.175 ( ±0.1mm) Length: 24mm/0.94" Quantity: 1Pc Note: Due to the difference between different monitors, the picture may not reflect  the actual color of the item. Thank you!.Note: Due to the difference between different monitors, the picture may not reflect the actual color of the item. Quantity: 1Pc.