... 2012 Heavy duty double ball bearing swivel pu castor Heavy Duty Caster /Four Size available (4'',5'',6'',8'')[Model Included] :KH42-H10 ... 2350kg to 370kg 3. .Caster material: PU wheel tyre with pp (nylon) core .this wheel core is adopted new latch technical .Wheel tyre ... .5.Zinc plating and Black Electrophoresis finishing available 6.Caster wheel can be changed to Pvc,rubber ,nylon ,pp ,tpr ,cast iron ...