... :Z1,Z2 3.Stocks 4.NBR co, Series 12(K), 22(K), 13(K), 23(K) aligning ball antifriction bearing Packing&DeliverPacking Detail:Standard ... ,bakelite retainer, etcMaterial:chrome steel,stainless steel,bearing steel Suffixes:CA: Integral brass cage, double row symmetrical rollers,inner ring rideMA ...