Listing is for a set of four (4) Service Caster Series #30 stainless steel casters, two (2) swivel casters with bolt on swivel locks and two (2) swivel casters with side lock brakes, with 4" diameter by 2" wide solid polyurethane wheel and maintenance free precision ball wheel bearings capable of supporting a total weight of 2,800 lbs. (700 lbs./caster).