4" x 2" Green Polyurethane on Cast Iron Core - 800 lbs Cap

4" x 2" Green Polyurethane on Cast Iron Core - 800 lbs Cap CasterHQ's Green Polyurethane elastomer tread is chemically bonded to a black cast iron core. Offers higher weight capacities while providing good floor protection and a smooth quiet rolling operation. Optional precision ball bearings require less effort to start-up and maintain a rolling load; they also generate less friction heat and may prolong the life of the wheel. Works well in both indoor and outdoor environments; however, a cast iron core can rust; if this is an issue look at using aluminum or plastic core wheels.