Brand: Sinn
Model: 142 BS Chronograph
Reference Number: 142
Year of Production: 1990s
Case Material: Black PVD-coated stainless steel
Caliber: Lemania 5100, automatic
Strap Material: PVD-coated stainless steel
Bracelet/Strap: Original NSA PVD-coated steel bracelet
Clasp/Buckle: Expanding deployant clasp signed Sinn
Dimensions: Approximately 44 mm
Gender: Men
Dial: Black, with tachymeter scale, chronograph subdials, 24-hour indicator
Condition: Excellent
Set: Full set
Signed: Yes (dial, case back, movement, bracelet)
Box: Yes
Papers: Yes

Launched in the 1990s, the Sinn 142 BS is a professional-grade chronograph designed for extreme conditions—including space missions, notably aboard the Spacelab D1. It is powered by the iconic Lemania 5100 caliber, offering excellent legibility with a central chronograph minute hand (arrow tip), 12-hour counter at 6, running seconds at 9, and 24-hour display at 12. The internal rotating bezel, operated via the crown at 10 o'clock, enhances its timing versatility. Aesthetically, it features a well-preserved black PVD coating and is fitted with a rare original NSA PVD-coated bracelet with signed expanding clasp. The condition is excellent, with minimal wear, and the watch comes as a full set with box and documents. A remarkable opportunity for enthusiasts and collectors looking for a space-era tool watch that still flies under the radar.

Case: round case made of stainless steel with a black PVD coating, a hallmark of Sinn's tool-watch aesthetic. The PVD treatment is in very good condition, demonstrating Sinn’s robust manufacturing standards. Screw-down case back ensures secure protection and water resistance. The case includes two crowns—one for time/date adjustment, and a second at 10 o’clock to operate the internal rotating bezel, used for timing.

Dial:matte black dial designed for functionality and legibility. The layout includes a central chronograph seconds and sweeping minutes hand with an arrow tip, a 12-hour totalizer at 6 o'clock, continuous seconds at 9 o'clock, and a 24-hour indicator at 12 o'clock. White print on the dial offers high contrast, and the day-date display at 3 o’clock is quickset via the crown.

Movement: powered by the Lemania 5100, one of the most revered automatic chronograph calibers used in military and aviation watches. Introduced in the 1970s, it features a unique central minute counter—uncommon in chronographs—enhancing readability. The movement is shock-resistant, capable of withstanding extreme conditions, and known for being reliable in both terrestrial and orbital missions. This caliber was famously used by Sinn in watches worn aboard the Spacelab D1 mission.