These are bearings combining two or more angular ball bearings in back-to-back arrangement, face-to-face arrangement, or tandem arrangement.
Face-to-face duplex (DF) or back-to-back duplex (DB) bearings can bear axial loads in both directions. Back-to-back duplex bearings have a higher moment load bearing capacity than face-to-face duplex bearings. Tandem duplex bearings can bear a larger single-direction axial load than single bearings.
Inquiry - NTN Duplex angular contact ball bearings
