... made of other material ,just like ceramic,plastic etc.)NO 1: Plastic bushing (blue,white colour,POMS,POMBS ... POMBT type;NO 2:Aluminum bushing(white,cupreous colour,ALBS,ALS,ALBM,ALM,ALBT,ALT type );NO ... want! Advantage1)We provide different mould accessories ,you can choose by different prices,different types.2)Abundant profession ... to give you the best service. different model of big size ball bearing