IWC introduced its first 'Grande Complication' wristwatch at the 1990 Basel watch fair. Building upon the platform that Kurt Klaus' perpetual calendar module had provided them, IWC went ahead and added a minute repeater to the already complex movement. The case measured 42.2mm across at a height of 16.3mm, making it of considerable size - especially at the time of introduction.Reference IW3770-05 has a yellow gold case and a silver / white dial with German markings.
