... .Rim:steel/plastic 4.Bearing:16,20,15,19 PU foam tyre 250-4Our factory is one of the leading manufacturers ... factory at any time ! More details:1.Model/typle: PU foam tyre, pneumatic wheel, solid wheel etc.2.Size : PU ... foam tyre(6x2,2.50-4,3.00-4,3.50- ...