A flyback chronograph exists for one reason: to restart timing instantly, with a single press, the moment one event ends and the next begins. Pilots used it to clock successive legs of a flight, and the Longines Spirit Flyback carries that function into a modern 42mm case with a black sunray dial and a leather strap.

Longines has a special claim here. The brand secured a patent for its flyback chronograph mechanism in 1936, and its timers accompanied many of the aviation pioneers of that era. Reference L3.821.4.53.2 is powered by caliber L791.4, an automatic column-wheel chronograph with a monocrystalline silicon balance spring, a frequency of 28,800 vph and roughly 68 hours of reserve. Like every Spirit chronograph, it is certified as a chronometer by COSC, and an open caseback lets you watch the mechanism at work.

The black ceramic bezel turns in both directions, handy for a countdown or a quick reference mark. At 17mm thick it has real presence, so it suits wearers who like a substantial sports watch, and the leather strap keeps it smart enough for the office.

Spirit Flyback 42mm Black on Leather, L3.821.4.53.2

• Case: 42mm stainless steel, 17mm high, screw-in crown
• Dial: sunray black with Super-LumiNova
• Bezel: bidirectional rotating, black ceramic insert
• Movement: L791.4 automatic column-wheel flyback chronograph, COSC
• Power reserve: up to 68 hours
• Back: sapphire display caseback
• Water resistance: 10 bar
• Strap: leather, double security folding clasp with micro-adjustment
• Lug width: 22mm

A chronograph with a patent-era backstory and the engineering to match it.