Entirely designed, developed and produced at the Officine Panerai Manufacture in Neuchâtel, the hand-wound P.3001 calibre presents the main characteristics of the Panerai movements both in terms of structure and in terms of performance, robustness and accuracy. The thickness of the P.3001 calibre is 6.3 mm and the diameter is 16½ lignes, a substantial size which traces its origins from that of the movements which were fitted to the historic Panerai models. The calibre is immediately recognisable by its construction, which is similar to that of a three-quarter plate movement: a large bridge, next to another smaller one, covers the majority of the mechanical parts, and is fixed to the bottom plate by a series of screws of substantial thickness, thus forming a particularly rigid structure. The movement has 21 jewels and it uses two spring barrels connected in series. The P.3001 has the power reserve indicator visible on the case back and may feature the date or GMT functions. The number of components varies according to the functions displayed on the dial.