The Urwerk U-100 was initially released in two different versions back in September 2019 under the Space-Time names. You can see the previous iterations of this watch here. The Urwerk UR-100 Space-Time was launched in two 25-piece limited editions, one referred to as UR-100 Iron in titanium and steel, and the second one UR-100 Black in black PVD-coated titanium and black PVD-coated steel. The Urwerk UR-100 was inspired by a 19th-century pendulum clock —a present to Felix Baumgartner from his father Geri, a now-retired renowned clock restorer— made by Gustave Sandoz for the 1893 World’s Fair in Chicago.