A rolling-element bearing unit includes at least one outer ring, at least one inner ring, a plurality of rolling elements disposed between the at least one outer ring and the at least one inner ring that are in contact with the at least one outer ring and the at least one inner ring and at least one auxiliary ring attached to an axial end region of the outer ring. The auxiliary ring may include a seal assembly and may be connected to the at least one outer ring with a snap fit.