Model: ER8 A Type; Material: Cast Steel Hole Diameter: 6mm / 0.24""; Overall Size(Approx.): 13 x 12 mm/ 0.51"" x 0.47"" (DH) This is a great replacement collet nut for the broken part; fit most tool holders Package Content: 1 x Clamping Nut Note: Different displays shooting and light may cause the color of the item in the picture a little different from the real thing. The allowable measurement is +/- 1-3cm error. Description: Precision and hardened mass. This collet nut is a great replacement for the broken part. Fit most tool holders. Specification: Product name: Clamping nut Model: ER8-A Size:13 x 12 mm/ 0.51"" x 0.47"" (DH) Thread size: M10 Thread pitch: 0.5mm / 0.02"" Hex Width: 12mm / 0.47"" Hole diameter: 6mm / 0.24"" Material: Cast Iron Package Contents: 1 x Hex Nut Clamp