I broke the wheel on my trailer dolly by moving it sideways on gravel with the tractor. Harbor Freight doesn't sell replacement wheels and I didn't want to buy a whole new trailer jack. 

I've not fully tested this yet. I'll update this Description when I've done more testing on it. It should fit anything with a ½ inch axle/bolt. It is 2" wide and 6" in diameter. 

I've included v2 but I've not tested it yet.

UPDATE:

Nearly a year in and it is still going strong! Last picture is for the update.