Swivel Caster/casters/wheels Spec.:3",3.5",4",etc. Materials:TPR Swivel CastersSpec.:2",3",4',5",6",etc.Material:hard rubber or PU,TPR.Color:Black,grey.we sell not only our swivel casters with good quality,but our best service to all our customers. 3.5 inch TPR Swivel Caster