The most complicated wrist watch ever made in the world








> Discover all details




The Genesis

From the outset, the primary aim of the AETERNITAS MEGA project was to produce an ‘extremely’ complex watch.

The second stage of the project involved the quest for noble complications to enhance what was going to become a genuine technical feat, i.e. the most complex wristwatch in the world.



The Model

The Research & Development department at Franck Muller Manufacturing focused on the volume and shape of the case, both essential aspects as regards the progress of the project.

Then came the dial production, which proved to be quite a tricky operation, as space needed to be found to display almost all of the complications at the same time as retaining a high degree of legibility. When designing the various mechanisms, their graphical representation on the dial had to be taken into consideration to ensure perfect compatibility.



The design of the mechanisms

Numerous problems were encountered when designing the mechanisms. However, one of the main difficulties experienced involved fitting the large Tourbillon into the space normally reserved for the Great Alarm. The other major difficulty was fitting the Great Alarm and its four hammers into a Curvex shaped case. Finally, the entire development of the secular date was a task that needed the highest level of watchmaking expertise.


The basic movement

The basic movement has a Cintrée Curvex shape. It’s an automatic movement with a micro-rotor placed at 6 o’clock and visible through the open-back. It has a grand tourbillon (Ø14mm) with a balance wheel with adjustment screws in platinum and no index.

It has a Breguet spiral and a Franck Muller conception escapement. The movement is equipped with a double barrel: the first barrel guarantees a power reserve of about 3 days; the second barrel provides energy for the Sonnerie. Each barrel has its own power reserve displayed on the dial.




Carillon Westminster

The Grande Sonnerie (Grand-strike) strikes the hours and the quarters automatically. The distinctive feature is that it chimes the same notes as the clock tower of the Westminster cathedral. For instance, at 3.15, the owner of the watch will hear 3 low pitch sounds (din din din) followed by the first four notes of the Westminster chime « mi do re sol ».

The Petite Sonnerie is programmed by a push-piece placed at 2 o’clock and it is displayed on the dial by a small hand. It only strikes the hours and the quarters (without repeating the hours at each quarter). For instance, at 3.15 the owner of the watch will only hear the first four notes of the Westminster chimes « mi do re sol ».


The Minute Repeater is activated on request by pressing a push-piece placed at 10 o’clock. It strikes the hours, the number of quarters and the minutes. For instance, at 3.20 the owner of the watch will hear (din din din) followed by the first four notes of the Westminster chime « mi do re sol » and then 5 low and middle pitch sounds (mi do mi do mi).

In order to prevent the user from any handling error, it is not possible to set the time during the chimes as well as chimes are not possible while the time setting is activated.





Perpetual Secular Calendar

A perpetual calendar indicates the day, the date, the month and the moon phases. It takes into account the length of each month and doesn’t require any manual intervention. This mechanism also takes into account the leap years, but it needs to be adjusted three times in a row every 100 years. According to the Gregorian calendar, every 400 years, the leap year is cancelled for three centuries in a row and is re-established on the fourth century. For instance, in 2100, 2200, 2300 and so on, the leap year is omitted whereas in 2400, and so on, it is re-established.


The eternal calendar of the Franck Muller Watchland workshops is different from any traditional perpetual calendar in that it takes into account the rule governing the Gregorian calendar stating that all century years not divisible by 400 are common years and not leap years.

The eternal calendar follows a cycle of 1’000 years (renewable to infinity) thanks to two additional sets of wheels:




The first set of wheels, comprising a wheel of 10 years, a wheel of 100 years and a wheel of 1’000 years, allows for the display of a cycle of 1’000 years.

The second set of wheels was designed for the setting, through the use of cams, of the skipping of the leap years three times in a row every 100 years and its re-establishment the fourth time.

On top of the usual indications – retrograde date at 12 o’clock, days, months, 24h day and night, normal leap year cycle – it also indicates the time equation. The equation of time is coupled with the calendar, which means that even when the watch is not wound for many years, at the moment of its correction, the equation of time follows the calendar. In addition to that, secular years are indicated through a red point placed at 2, which turns into green during the month of February of secular years.


Time Zones

On the lower side of the dial, two time zones with a 24 hour hand are placed on the left and on the right hand side of the tourbillon. It is possible to set the hour by pressing the push-pieces on the case. The push-piece on the lower right hand side sets the time zone placed on the right hand side of the tourbillon. As it was conceived for traveling eastwards, at each pressure the hand moves one hour ahead. The push-piece on the lower left hand side corresponds to the time zone placed on the left hand side of the tourbillon. As it was thought for traveling westwards, at each pressure the hand moves back one hour. Between the tourbillon and the center of the dial, the years from 0 to 999 are displayed in an aperture and the cycle can go on indefinitely.



The astronomic moon

On the dial, the moon phases are displayed with the utmost precision. The error is of only 6.8 seconds per lunar month which represents a deviation of only one day every 1000 years, whereas in a traditional system the error is of one day every four years.



The Aeternitas Mega is the pinnacle of success in the art of watch-making in terms of complexity and complications. A grandiose work of art culminating in the design of the most complex wrist watch ever made in the world thanks to the multifaceted skills of our watch-makers and constructors.

Each of the 1,483 components was designed to give the watch an elegant design in the pure traditions of the old “cadraturiers” of the Vallée de Joux, Switzerland.

This watch inspires countless emotions as an exceptional time piece and simply unique in the eyes of lovers of the art of fine mechanics and luxury watch making.

reference : 8888 MGA T CCR QPSE
Caliber :

FM 3480 QPSE

Movement :

Mechanic Tourbillon, Carillon Westminster on 4 hammers and 4 gongs, Chronograph with fly-back mechanism and only one push-piece, Perpetual Calendar Secular, Equation of time, Two additional time zones, Automatic self-winding mechanism for the movement and the Westminster carillon.

Power Reserve :

Movement : 3 days. Strike : 24 Hours

Frequency :

18'000 Alternances per hour.

Dimensions of the movement :

34.40 x 41.40. Height  13.65

Number of movement components :


Number of Jewels :


Movement decoration :

Côtes de Genève, diamond polishing, hand-bevelling, circular graining, bi-colour rhodium-plating and hand-engraving.

Display :

Hours, Minutes, 24 hours, Chronograph, Fly-back, Minutes counter, hour counter retrograde, two time zones, Movement power reserve.

Display of the strike :

Grande or petite strike. strike or silence. strike power reserve.

Perpetual calendar display :

Date retrograde, Day, Month, Year, Leap year (cycle of 4 years), no leap year (cycle of 100 years), leap year (cycle of 400 years), Equation of time.

Fonctions :

Winding-shaft with 2 positions. 7 push-pieces. 4 correctors

Dial :

Sun-stamped translucent lacquered white dial.

Case :

Cintrée Curvex 8880, 18 karat white gold.
Width: 42.00 mm  x Length: 61.00 mm  x Height: 19.15mm

Strap :

Hand-sewn alligator