... and specifications for your choice, also called ball bearing cage,ball bearing bushing ,& ball bearing bush,ball retainer & Die parts & die fittings for ... parts and prolong service life.6.sound quality steel ball retainer with excellent performance of hardness,glossiness,buildiness,abrasion ... ,ALBS,ALS,ALBM,ALM,ALBT,ALT type );NO 3:Copper bushing(copper-colored, CUS,CUM,CUT type).Also each type with ...