This stainless steel wristwatch just became the most expensive ever sold

An ultra-rare, one-of-a-kind Patek Phillipe watch sold at the Only Watch auction in Switzerland for a jaw-dropping $7.26 million this weekend.

It's the most expensive wristwatch ever sold in the public eye, according to Stephen Pulvirent at Bloomberg.

The estimate for the watch going into the auction was only $698,000 - $898,000, which the final price exceeded by nearly a factor of 10.

The model is a variation on Patek Phillipe's 5016 model, except that it's made with a stainless steel casing. The handsome watch includes a blue face and a few other interesting features, including a tourbillon which stabilizes the watch against the forces of gravity, a minute repeater which will chime the time on-demand, and a calendar that takes leap years into account.

Phillipes frequently dominate the lists of the most expensive watches ever sold, and they're highly sought after by collectors as investment pieces.

The Only Watch auction happens every year in Geneva, Switzerland. Ultra-high-end Swiss watchmakers donate rare and unique editions of their watches to be auctioned off, with the proceeds aiding the fight against Duchenne Muscular Dystrophy. This year's event auctioned off 44 watches and clocks and raised a total of $11.2 million for charity.

However, the $7.26 million price tag still can't touch the price of the most expensive regular watch ever sold: the Patek Philippe Henry Graves Supercomplication, a vintage pocket watch that sold at auction for $24 million last year.