Replacement wheel looks and fits exactly like OEM wheel it replaces and seems to be made from same material. I used 2 machine bushings (5/8" 14 gage) to reduce the amount of lateral play between wheel axle / hub. See picture. I also used a little silicone grease on axle shaft and bushings reduce the gap that will allow dirt to collect on the axel. Avoid petroleum based greases as it could react with plastic hub. The excess play could have been the reason why the original wheel failed when the cart was over-loaded and there was a sudden shift in load while traversing a hill.

Wheels were received with no packaging or markings to indicate that they are genuine OEM replacements for the Rubbermaid Commercial big wheel cart. I will assume that they are (based on Tractor Supply's description and the alarming price). But they are certainly different from the wheels originally supplied with my "Generation 2" cart. Those original wheels had fairly soft rubbery no-flat tires (not to be confused with the pneumatic tires on the "Generation 1" carts) and removable plastic axle bushings in the hubs. I imagine that these parts were originally intended to be replaced when the plastic bushings wore out. These new "Generation 3" wheels are designed differently, and -- in my view -- are of poorer quality. The wheel is one piece of molded plastic (no separate bushings). The "tire" is a softer plastic but is far too thin (no more than 1/16") to provide any cushioning. Unlike the earlier designs that this wheel replaces, the wheel is entirely flat across the width of its tread (i.e. where it contacts the ground). Rubbermaid has a good reputation for making tough products. If these "Generation 3" wheels are really OEM products and are made from the right kind of tough plastic, then they will likely be fine. However, it is evident that the design has suffered from cost-cutting, notwithstanding the price. Non-OEM 20" wheels manufactured by (starts with an M) and marketed as "perfect replacements" for the big wheel carts are much cheaper than these (despite featuring actual ball-bearing hubs), but many customers report that the plastic spokes break within a season or two of use. This is what I fear may happen with these expensive "OEM" wheels.