Favre-Leuba Bivouac 53213 watch vintage 1960s manual winding movement (P320) silver dial with barometric scale (mmHg), applied hour markers, steel-colored hour and minute hands, and red for the pressure indicator and seconds altitude calculation function with rotating bezel (unidirectional) stainless steel case - 40 mm excluding crown - 20 mm between lugs stainless steel case back - screw-down original Favre Leuba signed crown black grained leather strap - sport style - 7 and 11 cm total length 22.5 cm watch in very good condition and fully functional A few words about this historic piece: Favre-Leuba's Bivouac is a pioneering tool watch — the world's first wristwatch with a mechanical altimeter and barometer. Designed for mountaineers and explorers, this piece combines mid-century aesthetics with remarkable technical innovation. With its rotating bezel and pressure-sensitive module, it's more than a watch — it's a slice of horological history.