2012 Heavy duty double ball bearing swivel pu castor *Wheel dia.100-200mm *Cap.:235-370kgs ... 50 2012 Heavy duty double ball bearing swivel pu castor Heavy Duty Caster /Four Size available (4'',5 ... 3. .Caster material: PU wheel tyre with pp (nylon) core .this wheel core is adopted new latch technical ... 6.Caster wheel can be changed to Pvc,rubber ,nylon ,pp ,tpr ,cast iron,high-heat resistant material ...