Review on Aozel Threaded American Locking Casters by Jeremiah Small

3 out of 4 wheels were 1/2-13 and one was 12mm. Also, the nuts at the base of the studs were not the same size on 4 wheels. From other reviews I've read it seems like the seller stocks two different types and just puts whatever is in stock in one box and ships it. Obviously they are aware of this issue as they send you wrenches for all occasions but they were too thick and had to be ground down for use. They also only sent 1/2-13 nuts so I had to buy a 12mm nut. The wheels seem fine, but you have to solve all the problems they send you.