110 Small Rollers: Omnidirectional wheel is composed of 10 small rollers, which are made of plastic and coated with high quality silicone, having high friction. 2Wheel Hub: The inner ring of the wheel hub is made of plastic material, and the outer edge is composed of 2.2mm/0.09in thick high strength metal material. 3Omni Directional: Ensure maximum flexibility and freedom of movement, the vehicle can be quickly positioned in a narrow space, and the tires run with low noise. 4Stable Performance: The bearing capacity reaches 15kg / 529oz, which is stable, light, and non deformed, reliable performance, providing a good user experience. 5Product Size: Wheel diameter is approximately 60mm/2.4in, wheel thickness is approximately 24mm/0.9in, hex coupler is approximately 12mm/0.5in. Item Type: OmniWheel Material: Plastic + Aluminum Alloy Wheel Diameter: Approx. 60mm / 2.4in Thickness: Approx. 24mm / 0.9in Hex Coupler: Approx. 12mm / 0.5in Weight: Approx. 117g / 4.1oz 2 x OmniWheel