1.【Material】Made of pure copper material, specially heat-treated, high hardness and durability.2.【Sizes】Clamping diameter: 0.5mm/0.8mm/1.0mm/1.2mm/1.5mm/1.8mm/2.0mm/2.4mm/3.0mm/3.2mm (1/64 inch, 1/32 inch, 3 /64 inch, 3/64 inch, 1/16 inch, 5/64 inch, 5/64 inch, 3/32 inch, 1/8 inch, 1/8 inch).Total length: 17mm (43/64 inch), outer diameter of the shank: 4.3mm (11/64 inch), inner diameter: 3mm (1/8 inch)3.【Application】Compatible with most rotary tools such as hardware, hobbies, homes, etc.; suitable for installing drills, electric grinders, hanging mills, hoses, etc.4.【Function】Change the clamping capacity of the electric grinder and solve the blind zone of the clamping path. Its head is 4 claws, and the holding accessories are more stable. Choose from a wide range of sizes, suitable for more material sanding, to meet your multiple needs at once.5.【Tips】Please pay attention to the size of your original machine chuck before buying, otherwise it will not match. And allow some errors due to manual measurements.