This is a Favre-Leuba Bivouac Altimeter Barometer reference 53213. This tool watch features a mint original silver dial, a black bezel, and a manual wind movement. These watches were used by alpinists during the first climbs of the north side of the Matterhorn and in 1960s polar expeditions. The watch measured the drop in air pressure, warning them of incoming blizzards.

This watch has been serviced, including a crown replacement, and will come with a one-year warranty.