Well, if you check out their website everything is clear!
This is word for word the description you get before you buy one of these $3,500 bargains, although the emphasis is mine...
"The tuba, as we all know, is a big instrument. The subject of the tuba, as it turns out, is even bigger. It all begins with a peculiar-looking Mediaeval instrument made of wood and leather that was redesigned a number of times, first gaining keys, a straightened wood or metal body in two sections and even more keys, an upright configuration of graceful, wound tubing and valves, a circular design resembling a snake once more, and eventually culminating in the 4-valve BB flat compensating behemoth we all know and love today.
The tuba is an instrument for which there was a demand long before its creation. Various inventors sought to fill the desire of composers, bandmasters and orchestra conductors for an instrument that could supply the bottom end, especially in the days when orchestras were growing exponentially in size. Hector Berlioz’ remarks concerning the serpent and ophicleide are well-documented and uniformly uncomplimentary. To do these instruments justice, however, Wagner, who loved a lush tone-palate, wrote supporting passages for the serpent, and demand for the ophicleide remained such that it lasted until the early 20th century.
All instruments come complete with case and Machiavelli engraving to ensure its authenticity."
Seller says that he doesn't actually have any yet, but they'll be in real soon now and he'll get back to me on the description. Probably'll turn out to be a Chinese oval euphonium.