Longines Caliber L687

Brand	Longines
Caliber Number	L687
In-House?	No
Base Caliber	ETA A08.L91 (ETA/Valjoux 7751)
Movement Type	Automatic, self-winding mechanical
Lignes	13.25”’
Diameter	30mm
Height	7.9mm
Jewel Count	27 see comments below (25 in older versions)
Beat Rate / Frequency	28,800 bph / 4 Hz
Lift Angle	Unconfirmed
Power Reserve	54 – 66 hours (depends on variation)
Rotor Style	Ball-bearing
Hand-Windable?	Yes
Anti-Shock Device	Nivachoc or Incabloc
Chronograph System	Column wheel
Vertical Clutch?	No
Silicon Balance Spring?	Depends on variation
Regulator	Depends on variation
Hand Count	8
Functions	Central hours; central minutes; central chronograph seconds; small running seconds at 9:00; 24 hour indicator hand at 9:00; 30 minutes chronograph counter at 12:00; 12 hours chrono counter at 6:00; central pointer date hand; day of the week at 12:00; month at 12:00
Hacking Seconds?	Yes
Country of Manufacture	Switzerland, Swiss made
Known Models	Longines Master Collection Moonphase Chronograph (Add your watch to the comments below…)

The Longines caliber L687 is a triple-date moonphase movement found in the Longines Master Collection.

L687.2 VS L687.5:

There is a notable evolution in the calibre L687 with some important differences.

• L687.2 – Regular balance spring, ETACHRON regulator, Incabloc or Nivachoc anti-shock, 54 hours power reserve, 25 or 27 jewels (unconfirmed)
• L687.5 – Silicon balance spring, free-sprung balance wheel, Nivachoc anti-shock, 66 hours power reserve, 27 jewels

At the time of this caliber listing, the current variation is the L687.5 as seen in the image at the top of the page.

Functionality:

Setting the Calendar:

Longines warns against setting the calendar (including the moonphase) when the hands are between the hours of 7PM and 6AM.

Avoid this zone when setting your watch, otherwise you can damage the movement – even if it still runs, it could have unwanted results such as causing the day/date to flip at a different time than 12AM.

Additional Resources:

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Note: This caliber listing is still being updated, but feel free to start discussions on it in the comments below…