1. dia. 3",4",5' 2. swivel caster 3. available wheel materia PP,PU,TPR,etc. 1. medium-duty caster for shopping trollets,tray trolleys,low capacity bins,moveable shelving2. Be available for swivel, swivel with brake, threaded stem, threaded stem with brake,bolt hole, bolt hole with brake3. The available color is claret, purple black,black,white,blue,red and so on. medium-duty caster