The Drybox by Ondřej Stříteský is excellent. One of the steps is to cut down an 8mm (7.8mm) aluminum rod to size. This print is a replacement for that rod, as I don't have any on hand.
The print is a 7.9mm x 100mm cylinder, with the new Fuzzy Skin feature. PrusaSlicer 2.4 or newer is required. The fuzzy skin helps the bearings to have a better friction fit, as well as improves the rolling of the filament. It looks neat too.
The author remixed this model.