In 1990, IWC showcased their inaugural 'Grande Complication' wristwatch at the Basel watch fair. It was an impressive feat, as they built upon the existing Kurt Klaus' perpetual calendar module and even added a minute repeater to the movement. The case was a substantial 42.2mm wide and 16.3mm tall, making it quite large for its time. The IW3770-25 is part of the second generation of Grande Complications, easily recognized by its revamped dial and elegant 'dauphine' hands.