You're going to see differences like the wheel size the pin diameter whether or not there's will oiling or axle oiling whether or not they're lightened or have multi passages for oil to Splash or run into to lubricate the roller again pretty redundant.
Just pay attention to what they look like in the design a lot of them actually do feed oil toward the axle or needle bearings.
Which is another difference wheel on axle or needle bearing wheel and axle
