A caster cart is an undriven wheel that is designed to be attached to the bottom of a larger object to enable that object to be moved. A swivel caster. Casters are used in numerous applications, including shopping carts, office chairs, toy wagons, hospital beds, and material handling equipment.These cart casters are specifically designed for Food service carts/trolleys, all plastic bracket prevent rusting, Gray non-marking plastic caster wheels offer excellent floor protection, and are quiet and smooth-rolling, high capacity. 3",4" and 5" are available.