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 semi-steel cast iron wheel and maintenance free precision ball wheel bearings capable of supporting a total weight of 4,1,000 lbs. (1,200 lbs./caster).
- The top plate measures 4" x 4 1/2" with a bolt-hole pattern of 2.625" x 3.625" to 3" x 3" and can either be bolted or welded on.