The Vacheron Constantin Reference 57260, unveiled in September 2015 for the manufacture’s 260th anniversary, is a double-faced pocket watch in white gold with 57 complications. Sources give the component count as more than 2,800, and describe two dials, with multiple calendars and a double-retrograde split-seconds chronograph, among other functions. Dimensions are not stated here because I did not find a source I could confirm.

It was commissioned by a private collector, and reports say that three master watchmakers worked on it for around eight years. It surpassed the Patek Philippe Calibre 89 of 1989 as the most complicated watch, although the count of complications depends on how they are defined. Vacheron did not disclose the price.

The watch is seen as a showcase of what a manufacture can achieve rather than a collectable product. It is a unique piece and has never been in series production.