Review on Dr Luck Capacity Polyurethane Polypropylene Non Swivel by Marcus Rash

They are better than expected. Ball bearings are smoother than regular bearings, have grease fittings, and are adjustable to lock two in fixed positions so they won't spin while the other two spin 180 feet or just let all 4 spin. They look great on my newly made steel workbench. I am very happy. Would happily buy them again if needed.