Abstract: A conveyor ball unit comprises a conveyor ball resting on mounting balls in a mounting shell. A retaining ring is provided to hold the conveyor ball on the mounting balls in the mounting shell. The mounting shell can be set into an opening in a supporting structure and rests on the supporting structure by way of a shell rim. The unit is fixed in place by resilient first locking elements comprising in a first embodiment of the invention resiliently deformable projections which also define radial recesses in the interior of the mounting shell into which recesses projections formed on the retaining ring can be inserted in order to fix the ring within the mounting shell.