... :ZZ,RS 4,Noise level:Z1,Z2 double row cylindrical roller bearing 1,ABEC-3,5;Z2V2,Z3V3 2,High speed 3 ... level:Z1,Z2 double row cylindrical roller bearing is in line contact with the raceway, so the bearing can bear heavier radial load. Applications ... constant axial load.Lubrication Lubrication Groove &3 Holes in Outer Ring Structure Cylindrical roller bearings N series,NU series,NF series,NUP ...