These USA made wheels are designed to be used as replacement wheels for drywall dollies and sheetrock dollies. The listing is for a set of 4 wheels along with matching axels and nuts. These wheels features a crowned thermoplastic rubber tread the offers maximum floor protection, is non-making, and provides a smooth and quiet roll. Each wheel measures 8” in diameter and has a 2” wide tread. The axles size is 1/2” and the hub length (where the axle goes through) measure 2-1/2”. The capacity is 600 pounds per wheel and 2,400 pounds for all four wheels. If you have questions, please contact Mapp Caster, we are happy to help.