Dear, do you deal casters? We are professionally supply series of casters of cargo trolley,such as light &heavy duty casters,nylon casters, polyurethane casters,plastic casters,rubber casters,cast iron casters. They are widely used in tool box cabinet,handcart, hospital, transportation,material handling,furniture,scaffolding ,etc . Our company specializes in the production of casters, plastic carts, more than 1000 kinds of products. Casters are made of plastic, polyurethane and rubber and it's weigh from 1KG to 2 tons and are classified as light, medium and heavy. Would you like a few pieces samples for evaluation? if yes,feel free email me, Casters can be customized according to your requirements or size. Thanks Best regards Mike Professional Casters & Wheels Factory.