Product Information
* Factory: GS Factory
* Brand: Longines
* Collection: Master Collection
* Reference: L2.673.4.71.6
* Movement: Modified 7750 Automatic Movement
* Crystal: Sapphire Crystal
* Function Type: Multi-Function Automatic Watch
Technical Specifications
* Case Diameter: 42.1 mm
* Case Thickness: 14.3 mm
* Measured Weight: 174.4 g*
* Movement: Modified 7750 Automatic Movement
* Beat Rate: 28,800 BPH
* Crystal: Sapphire Crystal
*The measured weight of 174.4 g applies to the individual watch inspected in this QC report. Minor variations may occur between individual watches due to production tolerances and bracelet sizing.
Timegrapher Test Results
* Daily Rate: 0 Seconds/Day
* Amplitude: 255°
* Beat Error: 0.1 ms
* Beat Rate: 28,800 BPH
Testing Note
These readings were recorded from this individual watch during its pre-shipment QC inspection.
Mechanical movement performance may vary depending on mainspring power reserve, watch position, ambient temperature and testing conditions. The recorded results represent the movement’s condition at the time of inspection and should not be interpreted as permanently fixed daily performance.
Modified 7750 Movement Performance
This GS Factory Longines Master Collection L2.673.4.71.6 is equipped with a modified 7750 automatic movement, operating at 28,800 vibrations per hour.
During this QC inspection, the movement recorded a 0 seconds/day rate, 255° amplitude and 0.1 ms beat error.
The movement operated consistently under the recorded testing conditions. Because this is a multi-function watch, movement inspection should not be limited to timegrapher readings alone. Each available complication and adjustment function should also be operated and checked individually before shipment.
Functional Complications
One of the important characteristics of this GS Factory version is that the watch’s multiple functions are operational rather than simply decorative displays.
The corresponding functions and displays should therefore be tested through their complete operating cycles during pre-shipment QC.
This is especially important for a modified 7750 movement because the additional functions increase the mechanical complexity compared with a basic three-hand automatic watch.
A watch can produce acceptable timegrapher readings while still having an issue with one of its additional functions, so movement testing and functional testing should be treated as separate QC procedures.
Important Operating Considerations
This model requires more careful operation than a basic automatic watch.
Because several functions are integrated into the movement, incorrect adjustment or operating the functions at an inappropriate time can increase the risk of mechanical problems.
Owners should understand the correct operating sequence before adjusting the watch. Functions should never be forced if a crown, pusher or corrector feels unusually resistant.
Particular attention should be given to:
* Correct crown positions
* Correct pusher operation
* Calendar adjustment
* Chronograph operation
* Function switching
* Avoiding forced adjustment when resistance is felt
For this reason, the mechanical complexity of the watch should be considered before purchase. Buyers who prefer simple operation and minimal maintenance may find a basic three-hand model easier to own.
This does not mean the movement is unreliable. Rather, a multi-function mechanical movement naturally requires more careful operation than a simpler movement.
QC Observations
The GS Factory Longines Master Collection L2.673.4.71.6 demonstrated stable movement performance during this inspection.
The measured specifications of this individual watch were:
* Case Diameter: 42.1 mm
* Case Thickness: 14.3 mm
* Weight: 174.4 g
The modified 7750 movement recorded:
* Daily Rate: 0 Seconds/Day
* Amplitude: 255°
* Beat Error: 0.1 ms
A major advantage of this version is that its multiple functions can be operated rather than serving only as decorative elements.
At the same time, this mechanical complexity is also something buyers should understand before purchase. Incorrect operation can create unnecessary stress on the movement, particularly when adjusting calendar-related functions or using the pushers.
For this model, a complete QC inspection should therefore focus on both movement performance and actual operation of the complications, rather than relying only on appearance or timegrapher data.
Pre-Shipment QC Inspection
* ✔️ Modified 7750 automatic movement checked
* ✔️ Timegrapher readings recorded
* ✔️ Automatic winding function checked
* ✔️ Manual winding function checked
* ✔️ Time-setting function checked
* ✔️ Available complication functions individually tested
* ✔️ Chronograph operation checked
* ✔️ Chronograph start, stop and reset tested
* ✔️ Calendar-related functions checked
* ✔️ Crown positions inspected
* ✔️ Pushers and correctors checked
* ✔️ Case diameter measured at 42.1 mm
* ✔️ Case thickness measured at 14.3 mm
* ✔️ Individual watch weight measured at 174.4 g
* ✔️ Sapphire crystal inspected
* ✔️ Dial, hands and subdial alignment checked
* ✔️ Bracelet and clasp inspected
* ✔️ Exterior finishing and overall assembly checked
* ✔️ Final pre-shipment QC inspection completed
