I mounted these wheels on a motorized crane that I use outdoors to move large rocks that I use in sculpting. Because it's in the mud the little metal wheels that came with the crane didn't roll and now I can use those big wheels to lift a big rock and with a winch I can pull the crane to where I put the rock would like . Aside from buying a forklift, I don't know how to lift rocks, so these wheels became part of my "rock star," the "little crane that could."