This weekend, auction house Phillips sold a vintage Patek Philippe 1518 for an astounding $11,136,642 (including fees), making it the most expensive wristwatch sold at auction, ever, according to Hodinkee. The previous record was also a Patek Philippe, a one-of-a-kind stainless steel perpetual calendar with a minute repeater and a tourbillon that sold for $7.38 million last year.
So what makes this 1518 worthy of an eight-figure price tag? Made in 1941, the Patek Philippe 1518 was the very first watch to combine a perpetual calendar and a chronograph function in one watch. Furthermore, with a stainless steel case, this particular example is the rarest of an already rare timepiece. Only 281 1518s were ever made, the majority of which were yellow gold and rose gold — but Patek only ever made four 1581s in steel.