Listing is for a set of four (4) Service Caster Series #30 stainless steel casters, two (2) swivel casters with side lock brakes & bolt on swivel locks and two (2) swivel casters with a side lock brakes, with 6" diameter by 2" wide solid polyurethane wheels capable of supporting a total weight of 4,700 lbs. (1,200 lbs./caster).