Function: 1 Aluminum material with high strength and load bearing capacity and long service life. 2. Durable two-row wheels move 360° easily with swivel and lateral maneuverability. 3 Multiple rollers work securely and flex with almost lateral friction for stabilizing the robot or establishing a complete power transmission system. 4 The double-walled aluminum omnidirectional wheels are equipped with several rollers along the environment and rubber rollers to prevent slipping. 5 Each roller has two bearings to allow wheels to move easily and smoothly in any direction. Suitable for robot racing wheel 14054 Specifications: Item Type: Double Omni Wheelboards: 2 Number of Rollers: 18 Body Material: Aluminum Alloy Roller Material: Rubber Roller Bearings: Ball Bearing Capacity: 30kg / 66.1lb Roller Diameter: Approx. 19mm / 0.7in Wheel Diameter: Approx. 100mm / 3.9in Shaft Width: Approx. 29mm / 1.1in Weight: Approx. 362g / 12.8oz Compatibility: Suitable for robot racing wheel 14054Package List: 1 x omni wheel 3 x screw Note: 1 Please allow 0-1 inch differs due to manual measurement. Thanks for your understanding. 2. Monitor is not calibrated same. Item color displayed in photos may slightly differ from the actual object. Keep it standard and authentic.