... , high concentricity 4.No bubbles 5.Smooth surface ModelPU Ring wheel with aluminum core BrandKamidMaterial Nature rubber, NBR, PU, Silicone... DimensionPer drawing ... , Sintered Bronze, PlasticMOQ10pcsPriceBased on dimension & qtyWarranty6 months ~ 12 months. PU Ring Wheel with aluminum core, high precision, no bubble