Single row angular contact ball bearings are self-retaining units with solid inner and outer rings and ball and cage assemblies with polyamide, sheet steel or brass cages. The raceways of the inner and outer rings are offset in relation to each other in the direction of the bearing axis. The bearings are available in open and sealed versions. Their self-alignment capacity is very small.Double row angular contact ball bearings are units with solid inner and outer rings and ball and cage assemblies with polyamide, sheet steel or brass cages. They correspond in design to single row angular contact ball bearings in pairs in an O arrangement but give a narrower design than these. They differ in the size of their contact angle and the design of the bearing rings.