Double row angular contact ball bearings are units with solid inner and outer rings and ball and cage assemblies with polyamide or sheet steel cages. Their construction is similar to a pair of single row angular contact ball bearings in an O arrangement but they are narrower to a certain extent. The bearings are available in open and sealed designs. Due to the manufacturing processes used, open bearings can have turned recesses in the outer ring for seals or shields. Sealed bearings are maintenance-free and therefore allow particularly economical bearing arrangements. Due to the raceway geometry and the two rows of balls, the bearing can support forces in both radial and axial directions. They are therefore particularly suitable for use in pumps and agricultural machinery. Furthermore, double row angular contact ball bearings are used in applications including conveying equipment, packaging equipment, elevators and compressors. The angular adjustment facility of angular contact ball bearings is very limited. The adjustment angle should not exceed 2. Bearings of X-life quality have improved running accuracy and optimised surfaces. This gives a significant increase in the fatigue limit load of the bearings. In terms of the expanded adjusted rating life, values up to 50% are achieved. In certain applications, this means that a smaller bearing arrangement can be designed.