... linear bearingBest in quality linear ball cages in different types and specifications for your choice, also called ball bearing cage,ball bearing bushing ... of hardness,glossiness,buildiness,abrasion resistance,long service-life. The bushing has 3 types,which is made of steel( it can ... material ,just like ceramic,plastic etc.)NO 1: Plastic bushing (blue,white colour,POMS,POMBS,POMM,POMBM,POMT,POMBT type ...