Greubel Forsey’s first invention is an innovative double tourbillon mechanism (DT30), with one tourbillon – inclined at 30° and rotating in 60 seconds – inside another rotating every four minutes, to average out gravity-induced errors on the oscillator.
The DT30° Vision focuses on the visibility of the innovative invention, while the DT30° Secret has a closed dial merely hinting at the splendid treasure beneath.
The Double Tourbillon 30° system also lies at the heart of Invention Piece 1, although the displays, surfaces, architecture and aesthetics have all been profoundly developed in creating this exceptional timepiece. With paper.