Grande Complication 3770 Rose Gold / Ardoise / English

In Context

At 42.2 mm it is sized to the current mainstream: 40 mm is the median across every watch measured in this catalogue. At 16.3 mm it is very tall, and sits high off the wrist. The case back is closed, so the movement stays out of sight, and the sapphire crystal will resist everything short of deliberate abuse. Rated to 10 m, it is protected against rain and splashes and nothing beyond that.

The movement winds itself from the motion of your wrist. 44 hours of reserve carries it overnight, but not through a weekend in a drawer. At 28,800 vph the seconds hand advances 8 times a second.

IW3770-25 is one of 7 executions of the IW3770 base reference. Underneath they are the same watch; what separates this one is a grey sunburst dial and a rose gold case.

The 79091 is the movement of IWC's Grande Complication of 1990. It is a Valjoux 7750 base carrying Kurt Klaus's perpetual calendar and a minute repeater, decorated, assembled and regulated in Schaffhausen. It powers 17 watches in this library. It is the [79261](/calibers/iwc-79261)'s calendar, with its four-digit year and moon phase set from the crown, joined by a repeater that strikes the hours, quarters and minutes on two gongs, on the 7750's automatic chronograph; the [7750 piece](/blog/the-valjoux-7750-family) explains the base. The movement has 75 jewels, a 44-hour reserve and a beat of 28,800 vph, and IWC has made a few of them a year since 1990. The glossary defines the [grand complication](/glossary/grand-complication). In the library it powers 13 [Grande Complication](/brands/iwc/grande-complication) ref 3770 references at 42.2 mm, in platinum, yellow gold and red gold, and 4 [Portugieser](/brands/iwc/portugieser) Grande Complications at 45 mm. 4 are limited editions. The [18680](/calibers/iwc-18680) is the hand-wound movement of Il Destriero Scafusia, which added a split-seconds chronograph and a tourbillon to the same set.

16 other watches in the library run the IWC 79091.

IWC

Grande Complication 3770 Platinum / Black / English

IW3770-17 · 42.2 mm

IWC

Grande Complication 3770 Platinum / Silver / English

IW3770-13 · 42.2 mm

IWC

Grande Complication 3770 Platinum / Silver / German

IW3770-01 · 42.2 mm

IWC

Portugieser Grande Complication Platinum / Silver

IW3776-01 · 45 mm