Poly on Aluminum Caster Set with Roller Bearings 2 Swivel Lock 2 Rigid

The listing is for a set of four (4)service caster series#30 casters, two (2) swivel casters with bolt-on swivel locks, and two (2) rigid casters, with 6" diameter by 2" wide polyurethane on aluminum wheels capable of supporting a total weight of 4,800 lbs. (1,200 kg./caster).