This alarm watch was created to offer its wearer excellent readability and a useful complication. Its alarm function can serve as an audible reminder at any time of the day. This calibre has two barrels (power reserves). One is used to power the alarm, the other to power the basic functions. The great complexity of this movement lies in the fact that the oscillating weight supplies energy to the alarm barrel in one direction of rotation, and to the basic functions barrel in the other. This means that no manual winding is required for the alarm function.
In this case, Abraham-Louis Perrelet’s wonderful invention is devoted to replenishing two power reserves.