The Mini Spinner caster wheel is a rubber wheel (Thermoplastic Gray Tread/Polypropylene Black Core) with a load capacity of 275 lbs. Application usage: Good for food service, food processing, cafeteria, restaurant, kitchen medical hospital pharmaceutical, general purpose, and industrial applications. WARNING : This product can expose you to chemicals including Cobalt and Titanium Dioxide, which is known to the State of California to cause cancer. For more information, go to www.P65Warnings.ca.gov .