IWC · Grande Complication
Strap for Grande Complication 3770 Yellow Gold / Silver / English
Takes 18 mm straps. Verified lug width, the straps that fit this model, and answers to the most common questions.
Lug width
18mm
Lug width18 mm
Case diameter42 mm
ReferenceIW3770-21 (aka: 3770-21, IW377021)
FamilyGrande Complication
MovementIWC caliber 79091 hours, minutes, small seconds | date, day, month, perpetual calendar, year indicator | Chronograph | moonphase | minute repeater
Year1990 - 2010
CaseYellow Gold
Straps for the Grande Complication IW3770-21 (aka: 3770-21, IW377021)
Selected for the 18 mm lug width
Hammered Calfskin Strap Light Blue€98
Vintage Brown Calfskin Strap — Natural Patina€98
Hammered Pink Strap with Ecru Stitching€98
Hammered Yellow Strap with Ecru Stitching€98
Grey Hammered Leather Strap with Ecru Stitching€98
Swift Red Leather Strap€120
The Grande Complication IW3770-21 (aka: 3770-21, IW377021), seen from the bench
The IWC Grande Complication IW3770-21 is a high-complication timepiece featuring a 42.20 mm yellow gold case housing the caliber IWC 79091 movement. The watch combines a perpetual calendar, split-seconds chronograph, minute repeater, and moonphase indicator in a single mechanism. The lug width is 18 mm, specifically calculated to maintain visual and structural balance with the case diameter and depth.
The next step
The right strap isn't chosen. It is built, together.
From the atelier appointment to delivery, every step is made for those who know that things done well take time. Rare leathers, one piece at a time, eighteen months of warranty.
Request an appointment →Casati Milano · Via XX Settembre 15, Milan · by appointment only