... your choice, also called ball bearing cage,ball bearing bushing ,& ball bearing bush,ball retainer & Die parts ... ,buildiness,abrasion resistance,long service-life. The bushing has 3 types,which is made of steel ... like ceramic,plastic etc.)NO 1: Plastic bushing (blue,white colour,POMS,POMBS,POMM,POMBM,POMT ... ALS,ALBM,ALM,ALBT,ALT type );NO 3:Copper bushing(copper-colored, CUS,CUM,CUT type).Also each ...