Philippe Dufour · Duality

Duality No. 8

$4,000,000

The world's first wristwatch with a double escapement: two independent balance wheels averaged through a central differential, an idea borrowed from 1930s Vallée de Joux school pocket watches. Only nine Dualitys were completed; this 34mm pink-gold example, movement No. 8, is one of just three in pink gold and the last of the series. Sold for CHF 3,660,000 (about USD 4.0 million) at Phillips' Geneva Watch Auction: XIV in November 2021. Market-priced at auction — the figure shown reflects recent auction results.