Aluminum alloy wheels with optional inflatable tires or solid tires; 6 mm or 8 mm bearings optional; can be swapped and installed directly, saving time and labor. Easier to install and remove, reducing downtime and improving efficiency. Tires of the same model are largely compatible. Please review the images before ordering to confirm tire size and compatibility. High quality rubber materials create an optimal blend of raw materials, extending tire life. Grooved rubber surface provides excellent grip, anti-slip, wear resistance, and pressure resistance, while remaining light and durable and reducing rolling resistance. Improves overall appearance. Inflatable inner and outer tires offer better damping capacity and impact resistance than solid tires and remain flexible for maximum safety. Solid tires are easy to use, do not swell, pose no puncture risk, require no maintenance, and stay in top condition. This design enables the tire to withstand all pressure changes and, when fully inflated, to be as strong as a normal tire. Applications: - Warehouse carts and trolleys requiring quick tire changes with minimal downtime - Service carts and maintenance equipment in industrial or commercial settings - DIY projects or workshops that benefit from modular, compatible wheel/tire assemblies