In Jan-1980, one year after presentation of the innovative (--> Swatch & AP Ra-Tourbillon), ultra-thin (1.98mm) and important Delirium 1 by ETA (ESA-Quartz), Longines, Concord, Eterna and IWC the worldrecord was cracked again: the ladies-model was presented, the Delirium III with just 1.68mm thickness. The 18K-yellowgold case was 40% less voluminous and also made by the artists of Favre & Perret (yes, they made the PP3700- and PP3770-cases for Patek, too). The exclusive pieces were not less expensive than the men-models making them among the rarest Deliriums, these days.

The photo shows the sub-2mm Delirium 1 made by IWC and the Eterna-made ladies-variant Delirium III with less than 1.7mm.