... size customized Hardness: 62~67HRC steel ball material:GCr15 Best in quality linear ball cages in different types and specifications for your choice ... bushing (blue,white colour,POMS,POMBS,POMM,POMBM,POMT,POMBT type;NO 2:Aluminum bushing(white,cupreous colour,ALBS,ALS,ALBM ... .The compact Kind has more steel balls than the Standard type with the same specifications, it is more reliable when comparing ...