Rolex · GMT-Master II and Sky-Dweller
Rolex 126710GRNR vs Rolex 336934
11 published specifications differ between these two, and 4 are identical. Every figure below is what the manufacturer states for that reference; nothing is inferred from the other watch.
What differs
| Specification | ||
|---|---|---|
| Case | Oyster, 40 mm, Oystersteel. Monobloc middle case, screw-down case back and winding crown | Oyster, 42 mm, Oystersteel and white gold. White Rolesor — combination of Oystersteel and white gold |
| Diameter | 40 mm | 42 mm |
| Crystal | Scratch-resistant sapphire | Scratch-resistant sapphire, Cyclops lens over the date |
| Bezel | Bidirectional rotatable 24-hour graduated bezel, two-colour grey and black Cerachrom insert in ceramic, moulded numerals and graduations | Fluted, bidirectional rotatable Rolex Ring Command |
| Dial | Black, with highly legible Chromalight display with long-lasting blue luminescence | Intense white, with highly legible Chromalight display with long-lasting blue luminescence |
| Crown | Screw-down, Triplock triple waterproofness system | Screw-down, Twinlock double waterproofness system |
| Clasp | Folding Oysterlock safety clasp with Easylink 5 mm comfort extension link | Folding Oysterclasp with Easylink 5 mm comfort extension link |
| Calibre | Calibre 3285, Manufacture Rolex | Calibre 9002, manufacture Rolex |
| Movement | Perpetual, mechanical, self-winding, GMT function; bidirectional self-winding via Perpetual rotor | Perpetual, mechanical, self-winding, dual time zones, annual calendar; bidirectional self-winding via Perpetual rotor |
| Power reserve | Approximately 70 hours | Approximately 72 hours |
| Movement notes | Precision −2/+2 sec/day after casing. Second time zone with independent rapid-setting of the hour hand, 24-hour display, instantaneous date, stop-seconds. | Precision −2/+2 sec/day after casing. 24-hour display on an off-centre disc, second time zone, instantaneous annual calendar at 3 o'clock with rapid date setting, month shown through 12 apertures around the dial circumference. |
What is identical
Worth knowing as much as the differences: these are the specifications you cannot use to tell the two apart.
- Water resistance
- Waterproof to 100 metres / 330 feet
- Case back
- Screw-down
- Bracelet
- Jubilee, five-piece links, Oystersteel
- Certification
- Superlative Chronometer (official chronometer certification + Rolex certification after casing)
What the differences cost you
Each note below follows from the published figures in the tables above — what they mean for intake, for a listing, and for the handover. Nothing here estimates a price or a margin.
These reach different buyers
42 mm on the 336934 against 40 mm on the 126710GRNR. Diameter is a poor predictor of how a watch actually sits, but it is the field buyers filter on, so the two land in front of different people. Do not let one listing's photographs or copy stand in for the other.
One of these is a different asset to hold
The 336934 has a gold case and the 126710GRNR is steel. That is not just a price difference: a precious-metal case changes what your insurer needs told, how the piece should be stored and handled, and — in some jurisdictions — whether trading it puts you under a precious-metals rule your steel stock would not. Check your own city guide before you assume they are the same transaction.
Different movements to verify and to service
The 126710GRNR runs the Calibre 3285, Manufacture Rolex and the 336934 the Calibre 9002, manufacture Rolex. Two consequences at intake: the service history that is normal for one calibre is not evidence about the other, and the calibre is the check that catches a movement swapped into the wrong case. Confirm the movement matches the reference rather than assuming it from the dial.
What to check on each
126710GRNR
- Set the local hour hand forward and back in one-hour jumps and confirm it moves alone. The 24-hour hand and the minutes must stay put — that independence is the whole complication.
- Check where the two bezel colours meet. A two-colour Cerachrom insert has a defined transition, and it should sit precisely on the graduation rather than drifting to one side.
- Look along the Jubilee bracelet for stretch. Five-piece links mean many more pins than an Oyster bracelet of the same length, and Jubilees show their age in the hand before they show it in photographs.
336934
- Rotate the Ring Command bezel through each of its settings and confirm it selects cleanly. On this reference the bezel is the setting interface, so a bezel that does not index properly makes the complications unusable.
- Check all twelve month apertures around the dial circumference. Only one should be highlighted, it should correspond to the current month, and the others must read cleanly.
- Advance the date across a month boundary if you can. An annual calendar should step correctly at the end of a short month, and that is the one behaviour that distinguishes it from a simple date.
Sources
- Rolex official product page for reference 126710GRNR (GMT-Master II; Oyster 40 mm; Oystersteel) - Model case: Oyster; 40 mm; Oystersteel; Oyster architecture: monobloc middle case; screw-down case back and winding crown; Diameter: 40 mm; Material: Oystersteel; Bezel: bidirectional rotatable 24-hour graduated bezel with two-colour grey and black Cerachrom insert in ceramic and moulded numerals and graduations; Winding crown: screw-down with Triplock triple waterproofness system; Crystal: scratch-resistant sapphire; Water resistance: waterproof to 100 metres / 330 feet; Movement: perpetual; mechanical; self-winding with GMT function; Calibre: 3285; Manufacture Rolex; Precision: -2/+2 sec/day after casing; Functions: centre hour; minute and seconds hands; 24-hour display; second time zone with independent rapid-setting of the hour hand; instantaneous date; stop-seconds for precise time setting; Oscillator: paramagnetic blue Parachrom hairspring with high-performance Paraflex shock absorbers; Winding: bidirectional self-winding via Perpetual rotor; Power reserve: approximately 70 hours; Bracelet: Jubilee; five-piece links; Oystersteel; Clasp: folding Oysterlock safety clasp with Easylink 5 mm comfort extension link; Dial: black with highly legible Chromalight display with long-lasting blue luminescence; Certification: Superlative Chronometer — retrieved 2026-09-22
- Rolex official product page for reference 336934 (Sky-Dweller; Oyster 42 mm; Oystersteel and white gold) - Model case: Oyster; 42 mm; Oystersteel and white gold; Oyster architecture: monobloc middle case; screw-down case back and winding crown; Diameter: 42 mm; Material: White Rolesor - combination of Oystersteel and white gold; Bezel: fluted; bidirectional rotatable Rolex Ring Command; Winding crown: screw-down with Twinlock double waterproofness system; Crystal: scratch-resistant sapphire with Cyclops lens over the date; Water resistance: waterproof to 100 metres / 330 feet; Movement: perpetual; mechanical; self-winding with dual time zones and annual calendar; Calibre: 9002; manufacture Rolex; Precision: -2/+2 sec/day after casing; Functions: centre hour; minute and seconds hands; 24-hour display on off-centre disc; second time zone; instantaneous annual calendar at 3 o'clock with rapid-setting of the date; month display via 12 apertures around the circumference of the dial; stop-seconds for precise time setting; Oscillator: paramagnetic blue Parachrom hairspring with Paraflex shock absorbers; Winding: bidirectional self-winding via Perpetual rotor; Power reserve: approximately 72 hours; Bracelet: Jubilee; five-piece links; Oystersteel; Clasp: folding Oysterclasp with Easylink 5 mm comfort extension link; Dial: intense white with Chromalight display; Certification: Superlative Chronometer — retrieved 2026-09-22
Not affiliated with Rolex. Specifications are read from each manufacturer's own published documentation on the dates shown and may change; the manufacturer's current documentation governs.