A state-of-the-art bellow system, graphically represented by a temperature gauge, compensating for the oil’s expansion or contraction.


The bellows is a self-equilibrating pressure-balance system.

Our specially designed bellows extend or compress to compensate for changes in the oil's internal volume between -5 degrees and +55 degrees Celsius. This range covers all extreme temperature situations the watch might undergo. +10 to +40 degrees Celsius - the white zone - corresponds to the watchmaking industry's norm.


A mechanical gauge has been added to the ROCS 3 and ROCS 5 to precisely indicate the internal oil temperature - which is a mix of outside and wrist temperature. The 0.5 mm bi-metal spiral is mounted 0.1 mm under the discs to captures the slightest temperature change inside the oil.

The gauge can also be seen as a graphical representation of the compensation capacity of the seven bellows.

We fill and seal our TYPE 3 and TYPE 5 at -5 degrees Celsius.

At this temperature the oil has its minimum volume.