Product Information
* Factory: UFO Factory
* Brand: Rolex
* Collection: Cosmograph Daytona
* Reference: 126509
* Movement: 4131 Automatic Chronograph Movement
* Balance System: Free-Sprung Balance
* Version Tested: Standard-Weight Version
* Crystal: Sapphire Crystal
Technical Specifications
* Measured Weight: 143.2 g*
* Movement Type: 4131 Automatic Chronograph Movement
* Balance Architecture: Free-Sprung Balance
* Available Weight Versions: Standard-Weight / Weighted Version
*The 143.2 g figure represents the measured weight of the individual standard-weight watch inspected for this QC report. The weighted version and other configurations may differ, and minor variations can also occur between individual watches.
Timegrapher Test Results
* Daily Rate: +16 Seconds/Day
* Amplitude: 334°
* Beat Error: 0.3 ms
* Beat Rate: 28,800 BPH
Testing Note
Mechanical movement performance can vary depending on mainspring power, watch position, ambient temperature, and testing conditions. A single timegrapher reading represents the movement’s performance under the specific conditions of that test and may vary during normal daily wear.
The measured rate of +16 seconds/day is slightly above the internal QC reference range of 0 to +15 seconds/day. Further testing and movement regulation may be performed before shipment to confirm overall performance.
4131 Standard vs Free-Sprung Movement
UFO Factory Daytona models may be available with different 4131 automatic chronograph movement configurations.
Standard 4131 Movement
The standard version uses a conventional balance regulation system and provides automatic winding, timekeeping, and chronograph functions.
Free-Sprung 4131 Movement
The free-sprung version features a Free-Sprung Balance architecture, creating notable differences in the balance regulation system, movement layout, and visual details compared with the standard version.
This watch is equipped with:
4131 Free-Sprung Automatic Chronograph Movement
Therefore, Daytona models described simply as using a “4131 movement” may still have different movement configurations. The specific version should be identified as either the Standard 4131 or Free-Sprung 4131.
UFO Factory Free-Sprung 4131 Version
UFO Factory is among the earlier manufacturers in this market to introduce Daytona models equipped with a Free-Sprung 4131 movement configuration.
The Free-Sprung 4131 is one of the key technical specifications distinguishing certain higher-specification UFO Factory Daytona versions from standard movement editions.
Standard-Weight vs Weighted Version
UFO Factory Daytona models are also available in different weight configurations.
This watch is the:
Standard-Weight Version — Actual Measured Weight: 143.2 g
A separate Weighted Version is also available, using a different weight configuration to increase the overall mass and provide a different wrist feel compared with the standard-weight edition.
UFO Factory Daytona Version Configurations
Movement Options:
Standard 4131
Free-Sprung 4131
Weight Options:
Standard-Weight Version
Weighted Version
Even when two watches share the same Rolex Daytona 126509 reference, their movement architecture, weight configuration, and overall specifications may differ. The exact version should therefore be identified according to the actual movement configuration, QC specifications, and measured weight.
Pre-Shipment QC Inspection
* ✔️ 4131 movement operation checked
* ✔️ Free-sprung balance architecture inspected
* ✔️ Timegrapher performance recorded
* ✔️ Chronograph start, stop, and reset functions tested
* ✔️ Crown winding and time-setting functions checked
* ✔️ Individual watch weight measured
* ✔️ Sapphire crystal inspected
* ✔️ Dial, hands, and chronograph subdial alignment checked
* ✔️ Bezel and exterior finishing visually inspected
* ✔️ Bracelet and clasp operation checked
* ✔️ Final pre-shipment inspection completed
