The original Ref. 140 chronograph was a large cushion case design with semi-hidden lugs and an extra crown at 10 00 to rotate the inner bezel. It used a Lemania 5100 movement with an unusual configuration Chronograph seconds and minutes are counted with hands on the main dial and a 12 hour chronograph register is placed at 6 00. Small seconds is at 9 00 and the day and date is at 3 00. The original Ref. 140 also used a PVD coated steel case.
In 1985, a commercial Sinn 140 was brought to Spacelab by German astronaut Reinhard Furrer. This, along with the futuristic looks, earned it the name, “Space Chronograph”. This was the first automatic watch used in space, and proved that an automatic rotor would function correctly in zero gravity.
In 2012, Sinn relaunched the Ref. 140 Space Chronograph. The new model uses a modified Valjoux 7750 movement and TEGIMENT steel case but looks nearly identical to the original. The new movement has the same features and indications as the original but removes the day wheel, leaving only the date at 3 00.