Feature: 1. 360 Degree Rotatable: Installed the omni directional wheel in a fixed position, it can rotate 360 degrees and move flexibly. 2. Applications: Omni wheels compatible for Mindstorm are commonly used in industrial markets, ground and inversion applications, such as manual and electric transmission systems, feed rails, workstation turntables, robot wheels, etc. 3. Durable: The 48mm double row omni wheels are made of nylon and PE materials, which are durable and wear resistant. It is applicable to different environments and has low maintenance cost. 4. With Coupling: Equipped with plastic round and cross shaft couplings. The omnidirectional wheel is more sturdy, the fixing direction is clear, the installation is simple and stable, and the load stability is excellent. 5. Stable Performance: Durable construction and unlimited mobility make this Omni wheel ideal for harsh environments and industrial applications. Specification: Item Type: 48mm Omni Directional Wheel Material: Nylon, PE Gross Weight: 52g / 1.8oz Color: Black grey Wheel Diameter: 48mm / 1.9in Wheel Width: 26mm / 1.0in Roller Diameter: 13mm / 0.51in Wheel Aperture: 12mm / 0.47in Load Capacity: 2kg Applicable Models: For Mindstorm compatible hubs and other motors.. Package List: 1 x 48mm Omnidirectional Wheel2 x Coupling2 x Screws Note: 1. Due to manual measurement, 1‑3mm error is allowed, thank you 2. Due to the difference between different monitors, the picture may not reflect the actual color of the project.3. The round and cross shaft are presented as gifts. When matching, you need to use something to knock it in. After knocking it in, you may not be able to take it out. Please use it carefully.