Demand for these 41mm steel Aquanaut 5164's has been hard to keep up with. Presented on the versatile black rubber 'Tropical' strap with steel deployant clasp stamped with the Calatrava cross. This steel 5164A is powered by Patek's automatic calibre 324 SC with 'day/night' indications in apertures on the iconic black embossed dial and easy timezone change via the two pushers on the left side of the case. Complete with its original polished wooden Patek box, booklets, swing tag and Patek Certificate of Origin.