1.plastic caster wheel 2.materail:plastic+steel 3.color:black,grey,white,gold,blue etc ,various per customer requirement nylon caster wheel Features:1) Material: nylon2) Dia 30/40/50mm;3) With and without brake;4) Fixing with Metal pin, Screw stem or fixing plate as per your decision. Pin size :DIA.6*20 / 8*20/ 8*22/ 11*22 Scew stem size: Dia.1/4"*15" /1/4"*25" /3/8"*3/4" 5/16"*1-1/4" /5/16"*1-1/ ...