A 8 inches PU caster wheel is likely a caster wheel with a diameter of 8 inches, and the “PU” likely stands for polyurethane, which is a common material used for caster wheels. These wheels are often used in various applications such as furniture, carts, or industrial equipment to provide smooth and quiet movement. You can find such caster wheels in hardware stores, online marketplaces, or specialty shops that sell caster wheels and related equipment. Make sure to check the specifications and load capacity to ensure they meet your specific requirements.