... concentricity 4.No bubbles 5.Smooth surface ModelPolyurethane rubber wheel with bearing in BrandKamidMaterial Nature rubber, NBR, PU, Silicone... DimensionPer drawing or requestColormore ... , Steel, Sintered Bronze, Brass, Bearing, Many PlasticsBearing ChoicesBall, Needle, Sintered Bronze, PlasticMOQ10pcsPriceBased on dimension & qtyWarranty6 months ~ 12 months Polyurethane rubber wheel with bearing ...