I was just talking to a friend this morning and mentioning the beauty of the technology of the fancy internal gearing hubs for bicycles.
Simpler ones with 3 gears have been around for more than 100 years (the Sturmey Archer. a British brand, has been around that long), and more recent and higher tech models from Rohloff like the one in the photo are wonderful pieces of Engineering.
They are high quality, pricey but a peace of mind confort for a Touring cyclist -- as they are strong, functional and require much less care and maintenance than regular derailleurs during long trips.
Throw in some sandy roads, mud, and they shine even more - as they are all sealed and much less damage by the grit and mud.
Wikipedia has a good page for Rohloff : https://en.wikipedia.org/wiki/Rohloff_Speedhub
And Sheldon Brown as usual has a pristine page for the more mechanically inclined : https://sheldonbrown.com/internal-gears.html
User impressions about Rohloff hib bicycles: https://www.sheldonbrown.com/harris/rohloff-impressions.html
A similarly high end product with internal gearing (and all the advantages thereof, but this time mounted at the front end, near the bottom bracket and shifted there before transmission to the rear wheel) is the Pinion gear boxes.
Also a German product, these require frames specially built to accommodate them, but have a good reputation as well.
Here's their page for Touring bicycle gear boxes : https://pinion.eu/en/travel/
