... NBR, PU, Silicone...DimensionPer drawing or requestColormore than 30 colors or per requestHardnessShore 5A~ 95ATemperatureup to 300°CHub MaterialAluminum, ... Steel, Sintered Bronze, Brass, Bearing, Many PlasticsBearing ChoicesBall, Needle, Sintered Bronze, PlasticWarranty6 months ~ 12 monthsSpecial ... wear resistant PU wheel with axle shaft, High quality (Many hardness)