Short answer: the Sky-Dweller 326939 is a 42 mm Rolex in 18k white gold on an Oyster bracelet. It runs caliber 9001, an automatic movement with an annual calendar and a second time zone. Replica copies match the case size and the dial layout. They differ on case metal, weight, bezel action, and the calendar. Check those four points before you pay.
Genuine 326939 specs
- Case: 42 mm, 18k white gold, solid caseback, sapphire crystal.
- Bracelet: Oyster, three-piece links, Oysterclasp.
- Bezel: Ring Command. Three positions. It selects what the crown sets.
- Movement: caliber 9001, automatic, 72-hour power reserve.
- Calendar: annual, called Saros by Rolex. Month apertures sit at the hour markers except 3 o'clock.
- Second zone: off-center 24-hour disc.
- Date: 3 o'clock, Cyclops lens, 2.5x magnification.
- Water resistance: 100 m.
Rolex put the 326939 on sale in 2012. It left the catalog in 2023, when the Sky-Dweller moved to caliber 9002. A new 326939 today is old stock, pre-owned, or a replica.
How replica builds differ
Metal and weight
Gold alloy is denser than steel. A white gold Sky-Dweller weighs about a third more than the same case in steel. Replicas use 316L steel, 904L steel, or plated brass. Put the watch on a kitchen scale. A light 42 mm Sky-Dweller copy is steel. Plated brass is lighter, and the plating wears at the lugs and the clasp edges.
Ring Command bezel
On the genuine watch the bezel turns in three positions with clear detents. Each position changes the crown function. On most copies the bezel turns with no detents and does nothing, or the bezel is fixed. Turn the bezel a full circle and count the stops.
Annual calendar
The genuine caliber 9001 advances the month on its own at the end of each month. Replica movements use a modified ETA 2824, a Seagull base, or a clone 9001. On most copies the month apertures are fixed, painted, or set by hand with the crown. Ask one question: does the month window change by itself at the end of April?
24-hour disc
The genuine disc is driven by the movement and holds a set offset from local time. On many copies the disc turns with the hour hand. The second time zone then cannot be set to a chosen offset.
Crystal and Cyclops
Genuine crystal is sapphire with an anti-reflective coating under the Cyclops. The date reads black and sharp at an angle. Copies use sapphire or mineral glass. Check the date size and the reflection at 45 degrees.
Checks before purchase
- Weigh the watch. Write down the number.
- Turn the bezel. Count the detents. Three positions is the target.
- Pull the crown to each position. Set the date, the month, and the 24-hour disc.
- Look at the month apertures. They should line up with the hour markers and sit at the same depth.
- Measure the case. 42.0 mm across, crown excluded.
- Check the bracelet end links for gaps and the clasp text for stamped letters.
What no copy gets right
Case metal and the calendar. No replica at replica prices uses 18k white gold, and few use a working Saros module. Judge the watch as a look-alike, and judge the price against that. If a seller claims solid white gold and a genuine annual calendar, ask for a scale photo and a video of the month jump at the end of a 30-day month.