The Nautilus collection was introduced in 1976, inspired by the universal shape of a porthole found on virtually all maritime vessels. It has gained style through subtle and carefully calculated changes, while preserving its original spirit. Incorporating the Patek Philippe 324 S QA LU 24H movement, the new Ref. 5726 is the first Nautilus model with an annual calendar. It comes in a stainless steel case and is worn on an alligator strap. Its black dial, sleek and casually elegant, is designed for optimized legibility.