The "china special" you can find at a zillion outlets. We were surprised that the casters rolled as well as they did. I can't count on fingers and toes how many people have called and bought a set of our TireSkates after they couldn't budge their car on these. The set is only rated at 1000 lbs per dolly. It's a steel wheel with a steel shaft and no bearing. The force probably varies tremendously, depending on how well they greased the axle (if the mfg. did). The semi-steel wheel is kind of brittle and also rough on the floor, for those of you with painted or tile floors. Ours are non-marring.
