When the Angelus engineers set out to develop, design and manufacture the U40 Racing Tourbillon Skeleton, they went way beyond the confines of traditional watchmaking and took their cue from cutting-edge architecture and high-performance structural engineering, some of the worlds greatest supercars and aerospace-inspired technology. The result of their labours, which involved four years of intensive R&D, is the Angelus Tourbillon Skeleton A-300 calibre.