The 158 is interesting because it is a tribute to the Bundesehr 1550 SG flyback A flyback function on a chronograph watch, allows the user to reset the chronograph back to zero and start timing again with a single button press (no need to first stop the watch).
[Learn More] chronograph produced by Heuer in the 1960s and 1970s. In the 1980s, Sinn was contracted to refurbish these watches and as a result, some excess watches were released to the civilian market under the Sinn brand.
Later on, Sinn made a 200 piece limited edition in 2005 for the Japanese market with a manual wind Valjoux 7760 beating inside that stayed true to the original 1550. In 2008, Sinn released another 272 pieces this time with the 7750 inside and a day/date display at 3 o’clock. Following the 2019 collaboration with Revolution’s 155 Dark Star, Sinn introduces the 158 in 2020.