... ZB02/ EF-ZB03 Material:Nylon,PU, Rubber, Super artificial rubber. Size:v2' -5inche Caster is important compoent of Wei ... , carts,racks.There is caster iron rubber wheel ,super artificial rubber wheel ,PPwheel,phenolicaldehyde wheel ,ESD wheel,with elastic ,low noise ... when move it. It's divide two style:With brake &Without brake worktable PU 3' wheel caster ...