Deep groove ball bearing: 1.Material: chrome steel. 2.Noise Level Z1,Z2,Z3,Z4 3,GCR 15 ... .Material: AISI52100, AISI440C, AISI304, AISI316, Ceramic7.Retainer: PTFE, Nylon, PEEK Or Stainless Steel8.Bore Size:from 1mm to 300mm9.Outside Diameter ... , C4, C5Material: AISI52100, AISI440C, AISI304, AISI316...Retainer: PTFE, Nylon, PEEK Or Stainless SteelLubrication: Oil,grease,dryNoise Level: Z1,Z2,Z3,Z4Type ...