Poly on Steel Set with Roller Bearings 4 Swivel Lock 2 Brake

The listing is for a set of four (4) Service Caster series #30 casters, two (2) swivel casters with side lock brakes & bolt swivel locks, and two (2) swivel casters with bolt-on swivel locks, with 6" diameter by 2" wide polyurethane on cast iron wheels capable of supporting a total weight of 4,800 lbs. (1,200 lbs./caster).