A unique Patek Philippe wristwatch is now the most expensive timepiece ever sold, the Gulf News website reports. It fetched $31 million at the Only Watch charity auction in Geneva on Saturday evening, November 9.

This one-off Patek Philippe Grandmaster Chime Ref. 6300A-010 is the only stainless steel version of the Swiss manufacturer’s most complicated wristwatch, surpassing the value of the Patek Philippe Henry Graves Supercomplication pocketwatch, which sold for $24 million in November 2011.

The sale of the steel Grandmaster Chime represents more than 80 percent of the total money raised at the Only Watch 2019 Charity Auction this year, a total of $38.6 million. The bi-annual auction, organised by Monaco’s Monegasque Association against Muscular Dystrophy and conducted by Christie’s Watches, raises money to fund research on Duchenne muscular dystrophy. The premise of the charity auction is simple — leading brands donate a one-off timepiece to the auction. Since 2005, more than $40 million has been raised to finance fundamental and applied research in this field.

Back to the Patek Ref. 6300A-010: This was easily the most talked about timepiece in the lead-up to the auction. The watch, equipped with a reversible case, two dials and 20 complications had a pre-sale estimate of $250,000-300,000. Launched in 2014 on the occasion of the venerable watchmaker’s 175th anniversary, the Grandmaster Chime became part of the brand’s regular collection in 2016 but it was only available in precious metal.