What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
The Longines Master Collection Moonphase is a traditional mechanical dress watch with a date and a moonphase display. The current 40 mm steel L2.909.4.97.6 pairs a blue dial with a bracelet and is listed by Longines US at $3,450; the 34 mm steel L2.409.4.87.0 has a mother-of-pearl dial and alligator strap, listed at CHF 2,900. Both current pages specify a 25,200-vph automatic movement, up to 72 hours of power reserve and 3-bar water resistance. The choice makes most sense for someone who values classical styling and the moonphase’s visual appeal more than sports-watch toughness or maximum everyday utility.
What the Master Collection Moonphase is—and which watch these specifications describe
The Master Collection is a traditional Longines line; Hodinkee dates its launch to 2005. The current Moonphase configurations documented here are stainless-steel 34 mm and 40 mm models. They share the formal, round-case look and moonphase display, but differ in dial, bracelet or strap, market and price. Specifications should be matched to the reference number rather than generalized across every Master Collection Moonphase or similarly named Longines watch.
| # | Preview | Product | Price | |
|---|---|---|---|---|
| 1 |
|
The LONGINES Master Collection 40MM Automatic Watch | $4,100.00 | Buy on Amazon |
| 2 |
|
The LONGINES Master Collection 42mm Automatic Watch | $4,300.00 | Buy on Amazon |
| 3 |
|
The LONGINES Master Collection 42MM Automatic Watch | $4,400.00 | Buy on Amazon |
| 4 |
|
The LONGINES Master Collection 40MM Automatic Watch | $3,000.00 | Buy on Amazon |
| 5 |
|
THE LONGINES Master Collection 42MM Automatic Watch | $4,300.00 | Buy on Amazon |
| Reference and market | Case and dial | Movement and reserve | Crystal and water resistance | Band and price | Warranty |
|---|---|---|---|---|---|
| L2.409.4.87.0; Longines, 2026 | 34 mm stainless steel; white mother-of-pearl dial | Automatic moonphase movement; 25,200 vibrations per hour; up to 72 hours | Sapphire crystal with anti-reflective coating; 3 bar | Alligator strap with triple safety folding clasp; CHF 2,900 | Not stated on the Longines page cited for this reference. |
| L2.909.4.97.6; Longines US, 2026 | 40 mm stainless steel; sunray blue dial | Automatic moonphase movement; 25,200 vibrations per hour; up to 72 hours | Sapphire crystal; 3 bar | Stainless-steel bracelet with triple safety folding clasp; $3,450 | Five years, as stated on the Longines US page. |
The older black-dial 40 mm L2.909.4.51.7 is a different reference: a 2019 Longines specification sheet identifies its movement as calibre L899 and gives a 64-hour reserve, with an alligator strap, sapphire front crystal and display back. That documented figure should not be silently substituted for the up-to-72-hour figure on the current 2026 product pages.
How it looks on the wrist
The design is built around dress-watch cues: a classical round steel case, formal dial furniture, and a moonphase aperture paired with a date. Dial finish and markers vary by configuration. The Hodinkee-reviewed 40 mm model has a barleycorn pattern that evokes traditional guilloché, but the review explicitly distinguishes it from hand-guilloché work. Current examples also show how much the presentation changes with configuration: the 40 mm US model has a sunray blue dial and steel bracelet, while the 34 mm model has a white mother-of-pearl dial and alligator strap.
Recommended Free Tools
#1 Best Overall
- Automatic L687 movement, hours, minutes, small seconds with 24 hours indicator at 9 o'clock. date indicated by the half moon central hand. Moon phase display at 6 o'clock. Case, hours, minutes, small seconds with 24 hours indicator at 9 o'clock. date indicated by the half moon central hand. Chronograph mechanism : central 60 seconds hand, moon phase display with 12 hours counter at 6 o'clock, 30 minutes counter with day and month display at 12 o'clock. Transparent case back with sapphire crystal
- Stainless steel with triple safety folding clasp and push-piece opening mechanism
- 5 Year International Warranty
Choosing a size
Hodinkee’s reviewer found the 40 mm watch balanced on a seven-inch wrist. That is useful as a reference point, not a guarantee of fit: wrist shape, preferred overhang, strap or bracelet, and the watch’s proportions all affect how a case wears. The current 34 mm reference is the smaller documented option for buyers who prefer a more restrained footprint. Hodinkee also mentions a 42 mm option in its 2020 review, but that does not establish that a 42 mm Moonphase is part of Longines’ current range.
Movement, reserve and timekeeping
The current Longines pages for L2.409.4.87.0 and L2.909.4.97.6 specify an automatic moonphase movement beating at 25,200 vibrations per hour and up to 72 hours of power reserve. Longines’ 2019 sheet for the separate L2.909.4.51.7 names calibre L899 and gives 64 hours. Hodinkee’s 2020 review likewise identifies L899, describes it as based on ETA A31.L91, and reports 64 hours for the model it reviewed. These are reference- and documentation-specific figures, not evidence that every watch bearing the Moonphase name has one reserve figure.
Rank #2
- Automatic L687 movement, hours, minutes, small seconds with 24 hours indicator at 9 o'clock. date indicated by the half moon central hand. Moon phase display at 6 o'clock. Case, hours, minutes, small seconds with 24 hours indicator at 9 o'clock. date indicated by the half moon central hand. Chronograph mechanism : central 60 seconds hand, moon phase display with 12 hours counter at 6 o'clock, 30 minutes counter with day and month display at 12 o'clock. Transparent case back with sapphire crystal
- Brown Alligator strap with triple safety folding clasp and push-piece opening mechanism
- 5 Year International Warranty
The supplied specifications and cited reviews do not establish a measured daily accuracy result for the current references. A beat rate and power reserve describe movement operation and autonomy; they do not tell you how many seconds per day a particular watch will gain or lose. Ask the seller or an authorized service provider about the applicable accuracy standard and have a specific watch checked if measured performance is important to your purchase.
Is the moonphase useful, or mainly decorative?
For most buyers, the moonphase is primarily an aesthetic and horological complication: it adds a small moving representation of the lunar cycle and gives the dial more character, while the date is the more practical calendar display. It is not a substitute for a tool watch’s timing or environmental protections. The cited product descriptions do not specify a moonphase correction interval or provide operating instructions, so do not assume that a particular setting method applies to every reference; follow the manual for the exact watch when adjusting calendar indications.
Rank #3
- Automatic L687 movement, hours, minutes, small seconds with 24 hours indicator at 9 o'clock. date indicated by the half moon central hand. Moon phase display at 6 o'clock. Case, hours, minutes, small seconds with 24 hours indicator at 9 o'clock. date indicated by the half moon central hand. Chronograph mechanism : central 60 seconds hand, moon phase display with 12 hours counter at 6 o'clock, 30 minutes counter with day and month display at 12 o'clock. Transparent case back with sapphire crystal
- Stainless steel with triple safety folding clasp and push-piece opening mechanism
- 5 Year International Warranty
A more complicated calendar can demand more attention when it needs correction. Fratello’s 2014 review of the distinct L2.673.4.78.3—an earlier 40 mm chronograph/calendar model, not either current reference in the table—warned that correcting its day, date, month and moonphase required care and consultation of the instruction manual. It uses calibre L678, based on ETA/Valjoux 7751, with 28,800 beats per hour and a 48-hour reserve. Those specifications and setting complexity belong to that multi-function reference, not to the current L2.909 or L2.409 models.
Water resistance and ownership costs
Both current references are rated at 3 bar. That rating makes the Moonphase a poor choice for someone seeking a carefree swimming, water-sports or rugged daily watch. Treat it as a dress-oriented mechanical watch and follow Longines’ guidance for water exposure, especially as seals age or after service.
Rank #4
- Automatic L899 movement, hours, minutes, seconds, and date and moonphase at 6 o'clock Transparent case back with sapphire crystal
- Stainless steel with triple safety folding clasp and push-piece opening mechanism
Mechanical watches require upkeep, and added complications can increase the work involved. Fratello notes of the more complicated L2.673.4.78.3 that servicing a watch with all those complications takes more time and effort than servicing a time-only watch. The cited sources do not provide a current service price or interval for the two current references, so budget for service through a qualified provider rather than relying on an unsupported estimate. Check the warranty terms for the exact market and reference as part of the total ownership calculation.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Price and value by reference
As listed by Longines in 2026, the US 40 mm steel L2.909.4.97.6 costs $3,450, while the 34 mm steel L2.409.4.87.0 is listed at CHF 2,900. Those are prices for different configurations in different markets and currencies; they are not a like-for-like comparison or a universal price for the collection. Historical review prices are also tied to their own models and dates: Hodinkee listed its reviewed 40 mm black-dial watch at $2,350 in the 2020 review context, and Fratello listed the L2.673.4.78.3 at €2,470 in 2014. They should not be read as a price trend because the references, markets and dates differ.
Quick wins for a faster PC:
Fix the driver behind crashes, sound loss and screen glitchesFind Drivers →Clear out junk files and repair common Windows errorsFree Scan →Scan for outdated or missing drivers - takes under a minuteDriver Scan →Best Value
- Automatic L687 movement, hours, minutes, small seconds with 24 hours indicator at 9 o'clock. date indicated by the half moon central hand. Moon phase display at 6 o'clock. Case, hours, minutes, small seconds with 24 hours indicator at 9 o'clock. date indicated by the half moon central hand. Chronograph mechanism : central 60 seconds hand, moon phase display with 12 hours counter at 6 o'clock, 30 minutes counter with day and month display at 12 o'clock. Transparent case back with sapphire crystal
- Stainless steel with triple safety folding clasp and push-piece opening mechanism
- 5 Year International Warranty
Value depends on whether the classical dial, mechanical movement and moonphase display are the point of the purchase. A buyer choosing for complication charm and formal versatility may find the proposition appealing; a buyer comparing watches chiefly on water resistance, utility per dollar, or low-maintenance practicality has stronger reasons to look elsewhere. Before deciding, compare the exact reference’s fit, dial and band, movement documentation, water resistance, warranty and likely service needs.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
