====== Greubel Forsey GMT Quadruple Tourbillon ======
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**GMT Quadruple Tourbillon** is a luxury wristwatch from [[Greubel Forsey]].

New edition of the previous model in white gold, this time (February [[2021]]) in titanium case and with sporty design. Although products of the highest rank are to be expected from the brand anyway, this model also represents a top performance within the in-house range.

The
Quadruple Tourbillon is Greubel Forsey’s second
Fundamental Invention, The mission: to average
out positional errors due to gravity in all situations,
especially in stable wristwatch positions.
To achieve this, the original tourbillon has been
elevated to realise its full potential: inclined at
30°, doubled and then quadrupled. The result,
two synchronised Double Tourbillon 30° mechanisms,
where a first cage, inclined at 30° and
rotating in one minute, is nested within a second
horizontal cage, completing a full rotation in four
minutes. A spherical differential transmits the
average timing rate of the four tourbillon cages,
improving the overall chronometric performance
of all the regulating organs.

Planet Earth, set near eight o’clock, shines in a
new light with the blue livery. An original Greubel
Forsey creation from ten years ago (2011), the
rotating terrestrial globe allows for the simultaneous
display of several different time zones: on the dial side, with a 24-hour ring around the
Earth, for Day/Night indication and on the caseback side, displaying 24 major cities their
respective time zones while distinguishing between those which use summer time (on a
light coloured backdrop), and those which do not (on a dark backdrop).

The sapphire crystal window around the equator completes the timepiece, offering a complete
view of the Earth in motion, with its continents immersed in the deep blue ocean waters, complementing the exquisite blue finish of the power reserve, hour circle and strap.

<WRAP ud ud_mod>
**Movement:**
  * [[Manufacture caliber]] with manual winding, 21,600 A/h.
  * Inner tourbillons inclined at an angle of 30°: 1 revolution per minute
  * [[Outer tourbillons]]: 1 revolution in 4 minutes
  * [[Triple barrel]]
  * 84 jewels
  * 705 components
  * [[Power reserve]] 72 h

**Case:**
  * [[Titanium]]
  * Curved brushed titanium bezel with polished flanks
  * Ø 46.5 mm, H 17.45 mm
  * [[Sapphire crystal]], asymmetrically curved
  * Sapphire crystal back	 
  * [[Waterproof]] to 3 atm

**Dial:**
  * Multi-level in gold, anthracite colour
  * Gold hour ring and power reserve
  * Gold hour markers

**Functions:**
  * Hour, minute, [[small second]]
  * [[Power reserve indicator]]
  * [[GMT]] function: 2nd time zone • rotating globe with universal time and day-and-night • universal
  * Time on 24 time zones • cities observing summer time • lateral window showing the equator
and southern hemisphere

**Wristband:**
  * Rubber or hand-sewn alligator with [[folding clasp]]

**Limitation:**
  * 11 pcs.

**Price:**
  * 760.000 CHF (2021)
</WRAP>

===== Video =====
  * [[https://youtu.be/82ulwkxdlpQ|Greubel Forsey GMT Quadruple Tourbillon]], YouTube, 0:59

{{tag>Watch_models GMT_watches Watches_with_Tourbillon Greubel_Forsey_models}}