Rubber Threaded Casters

They're smooth and good breaks. An extra 4 nuts would help leveling.

Extra castor is required since it only comes with three. Castor is work really well.

Well worth the money. These are not like what you’re going to get at the big box store down the block or the big box store on your phone. These are really nice substantial casters and they make a big difference regarding the ease of moving your wire shelving.