Features: brand new and high quality Center shaft hole: 3.17mm. Chuck clamping 0.3-3.4mm. Package Includes: 1x Electric Motor Shaft Mini Chuck. High Quality Material: Made of high quality carbide+ brass, stable, firm and durable. The material of the center shaft is brass, and each set is equipped with a small hexagonal wrench. Specifications: Material: Carbide+ Brass Color: As the Picture Shows Product Dimension: approx. Shaft Hole Diameter: 3.17mm/0.12inches Clamping 0.3-3.2mm/0-0.13inches Net Weight: 20g/0.04lbs Package Includes: 1x Electric Motor Shaft Mini Chuck note: Please allow 1-2cm errors due to manual measurement. Due to the difference between different monitors, the picture may not reflect the actual color of the item.