Read the hands and 24-hour bezel as one display
The genuine GMT-Master II uses ordinary hour, minute and seconds hands plus an arrow-tipped hand that completes one circuit in 24 hours. The arrow hand is read against a bidirectional 24-hour bezel. Genuine reference 126710BLNR is a 40 mm design with a blue/black bezel and independently adjustable local-hour display; its original movement is calibre 3285.
The old blue/black watch photograph on this page illustrates where the extra hand and numbered bezel sit. Its advertising wording does not identify the movement inside a supplied replica or establish current availability. A working extra hand must be observed against time and during adjustment, not inferred from its appearance.
Which hand adjusts independently?
| Situation | Independent local-hour hand | Independent 24-hour hand |
|---|---|---|
| Arriving in another time zone | The ordinary hour hand can jump to local time while minutes and reference time remain undisturbed. | Changing ordinary local time may require resetting the main time display, depending on the movement. |
| Staying at home, following another city | The reference display can be arranged during the initial setting; local-hour adjustment is chiefly useful when travelling. | The extra hand can be set to the other city's hour without changing ordinary local time. |
| Crossing local midnight | Observe whether the date follows the local-hour change in the directions the actual movement permits. | Observe how the calendar is set; do not assume changing the extra hand changes the date. |
| Evidence that distinguishes them | A demonstration moving the ordinary hour hand independently of the minutes and arrow hand. | A demonstration moving the arrow hand independently of the ordinary time display. |
A GMT hand can also be coupled to the main display without either independent adjustment. That may provide a day/night indication but does not establish the same setting flexibility. The movement function checks explain how to record the actual behaviour without relying on a copied “3285” label.
A complete reading example with fixed offsets
This is an illustrative time calculation using two fixed zones: UTC and UTC+8. Neither zone in this example changes for daylight saving time. It is not a measurement of a particular replica.
- At 09:30 UTC, the time in UTC+8 is 17:30 on the same date.
- With the bezel's zero/24 marker aligned at 12 o'clock, set the 24-hour display to 09:30 UTC according to the actual movement's instructions. The arrow points to the 09:30 position between the bezel's 8 and 10 markings.
- The ordinary display for UTC+8 reads 5:30, with the 24-hour context making clear that it is 17:30. Both displays share the minute reading of 30.
- In a demonstrated independent-local-hour mechanism, changing the ordinary hour by eight hours should leave the minute and UTC reference display undisturbed. With independent 24-hour setting, the same final display can be arranged by a different setting route.
At 00:30 in UTC+8 on the following date, UTC is still 16:30 on the previous date. This makes a useful observation point for the local date display. Record what the installed mechanism actually does; the extra hand's presence alone does not prove its date relationship.
A rotated bezel changes the scale used to read the arrow hand. Return it to the aligned position for this example, and keep bezel position in the record so a changed reading is not mistaken for movement drift.
Match colour, crown side, date position and bracelet
| Full reference configuration | Bezel | Crown and date | Bracelet in this example |
|---|---|---|---|
| 126710BLNR-0002 | Blue and black, 24-hour scale. | Right-side crown; date at 3 o'clock. | Jubilee, five-piece link pattern. |
| 126720VTNR-0002 | Green and black, 24-hour scale. | Left-side crown; date and lens at 9 o'clock. | Jubilee, five-piece link pattern. |
These specific configurations are design references. Other configurations must be identified separately, and the table makes no claim about a seller's replica inventory. A colour nickname does not tell you the crown side, supplied bracelet or independent-hand mechanism.
Crown side affects how the case meets the wrist and sleeve. Bracelet articulation, actual case thickness, rigid span and the sized clasp position affect fit. Record those measurements for the supplied version rather than applying the genuine 40 mm designation as a complete fit specification.
Choose the mechanism before the nickname
For frequent time-zone changes, prioritise verified local-hour adjustment and its date behaviour. For a home-based second-zone display, prioritise verified extra-hand adjustment and a clear 24-hour reading. Save both the selected configuration and the demonstration result in the inspection record.
The Explorer II's fixed 24-hour bezel offers a different visual and functional arrangement. The Submariner's 60-minute bezel is an elapsed-minute scale, so its numerals and operating purpose should not be used to judge this GMT display.