... bushing (blue,white colour,POMS,POMBS,POMM,POMBM,POMT,POMBT type;NO 2:Aluminum bushing(white,cupreous colour,ALBS,ALS,ALBM ... ,ALM,ALBT,ALT type );NO 3:Copper bushing(copper-colored, CUS,CUM,CUT type).Also each type with the Standard Kind,the ... .The compact Kind has more steel balls than the Standard type with the same specifications, it is more reliable when comparing ...