Oris Calibre 400: why an automatic needs two barrels and five days of power

Oris · Calibre 400

The movement in detail

The movement’s idea

01Five days of power make particular sense if you change watches several times a week. According to its stated reserve, a fully wound Oris with Calibre 400 taken off on Friday can run until Wednesday. The movement has two barrels with extended mainsprings: Oris assigns roughly two and a half days of energy to each. Here, long autonomy is built into the architecture, rather than explained by a name on the case back.

02Oris developed Calibre 400 itself. It is an automatic movement measuring 30 mm in diameter, running at 4 Hz, with a 120-hour reserve. An important distinction: 30 mm is the movement's size, rather than the watch's on the wrist. The calibre is fitted to different Aquis, Divers Sixty-Five and ProPilot X cases, so fit and dimensions must be assessed for the chosen model.

03The rotor has a less visible but intriguing change. Instead of a conventional ball bearing, Oris uses a low-friction slide bearing. The brand connects this solution with reduced wear and more efficient automatic winding. For an owner, the attraction lies in the intended long working life of a component that moves constantly while the watch is worn.

Practical meaning

04Oris states a daily rate of −3…+5 seconds and more than 30 non-magnetic components. In the brand's test, after exposure to a field of 2 250 gauss, the deviation was less than 10 seconds per day. This is a specific test, rather than a promise of the same result in every environment. Rate accuracy and resistance to magnetic fields are best treated as separate movement properties.

05The boldest promise is a recommended service interval of ten years. The ten-year warranty applies to watches registered with MyOris; it does not eliminate water-resistance checks or the consequences of accidental damage. Before buying, I would find out where Oris watches can be serviced in your city and how registration works: those conditions matter more than a round number.

06Calibre 400 does not require choosing a watch solely for “120 hours”. Oris's official page shows both Aquis and ProPilot X watches with this movement, with different cases and prices. In a collection where watches are rotated, the long reserve really can reduce repeated time and date setting. If the watch is always on your wrist, the size and comfort of the particular case may matter more.

Enlarge