Reference 5396 was introduced to the market in 2006 in pink gold and pays tribute to the firm's celebrated Calatrava model, launched in the 1930s. The smooth pink gold case is of the distinctive, classic round Calatrava style of reference 96 and stands out by its large size. The appealing graphic design of the dial is inspired from a late 1930s historical "Calatrava" wristwatch, on permanent exhibition at Patek Philippe's prestigious museum in Geneva. Matching perfectly with the 18k pink gold case, the dial is blue with diamond hour markers and offers an excellent legibility to its wearer, with a day and month aperture typical of the 1940s and 50s, and a date mentioned at 6 o’clock alongside a 24 hour indication with moon phases.