====== Greubel Forsey Double Tourbillon 30° Technique ======

{{wst>image_cr|Greubel Forsey|Double Tourbillon 30° Technique Red Gold|270px}}
{{wst>image_cr|Greubel Forsey|Double Tourbillon 30° Technique Blue|270px}}
{{wst>image_cr|Greubel Forsey|Double Tourbillon 30° Technique Sapphire|270px}}
{{wst>image_cr|Greubel Forsey|Double Tourbillon 30° Technique Ceramic|270px}}

**Double Tourbillon 30° Technique** is a luxury wristwatch by [[Greubel Forsey]].

See:
  * [[Greubel Forsey Double Tourbillon 30°]]

Greubel Forsey's first invention, presented in [[2004]], was an innovative double [[tourbillon]] mechanism (DT30), with one tourbillon -- inclined at 30° and rotating in 60 seconds -- inside another rotating every four minutes, to average out gravity-induced errors on the oscillator.

<WRAP ud ud_mod>
**Reference:**
  * GF02s Technique, [[2014]]
  * Technique Blue [[2018]], Technique Black [[2017]]
  * Technique Sapphire, [[2016]]
  * Technique Ceramic, [[2019]]

**Movement:**
  * [[Manual winding]] [[manufacture movement]], 21,600 A/h
  * [[Balance spring]] with [[Phillips terminal curve]]
  * Two [[tourbillon]]s, the inner inclined 30°, with circulation time 1 minute, the outer with circulation time 4 minutes
  * Four coaxial series-coupled fast-rotating [[barrel]]s (1 turn in 3.2 hours)
  * 43 [[jewels]]
  * Olived-domed jewels in gold [[chatons]]
  * 396 parts
  * [[Power reserve]] 120 h

**Case:**
  * [[Platinum]] / [[white gold]] / [[red gold]] / [[titanium]]
  * Bi-color edition: [[Red gold]] + [[platinum]]
  * Black edition: Black ADLC [[titanium]]
  * Blue edition: Titanium, platinum or white gold
  * Ø 47.5 mm, H 16.84 mm 
  * Sapphire edition:
    * [[Sapphire]]
    * Ø 49.95 mm, H 17.15 mm
  * [[Sapphire crystal]] domed and transparent caseback
  * [[Waterproof]] to 3 bar

**Dial:**
  * Black, openworked

**Functions:**
  * Hours, minutes, [[small seconds]]
  * [[Power reserve indicator]] via circular arc

**Bracelet:**
  * Black hand-sewn alligator strap with [[folding clasp]]

**Limitation:**
  * 22 pieces
  * Blue edition: 33 pieces
  * Sapphire edition: 8 pieces, only US market
  * Ceramic edition: 11 pieces, only US market
</WRAP>


{{tag>Watch_models Watches_with_tourbillon Greubel_Forsey_models}}