Greubel Forsey Invention Piece 2 Why you need it: In 1999, Robert Greubel and Stephen Forsey began working on a new generation of tourbillon specifically designed to improve the timekeeping of the mechanical watch. In 2003, they unveiled the Greubel Forsey brand with their innovative Double Tourbillon 30°. The IP2 is offered in a unique edition of 11 pieces in platinum and 11 pieces in 5N red gold