ETA · ETA 2892-A2

Omega Seamaster 300M, IWC Mark XVII and Hamilton Intra-Matic power reserve: inside the ETA 2892-A2

The 1990s Omega Seamaster Professional 300M, the IWC Pilot's Watch Mark XVII, the Cartier Ballon Bleu and the Hamilton Intra-Matic 38 all run on the ETA 2892-A2 or a version of it. From full it lasts about 42 hours, just under two days.

Updated September 2026 · Based on manufacturer specs, published reviews and watchmaker/owner reports

Watches that use the ETA 2892-A2

The 2892-A2 was ETA's premium automatic: thinner and better finished than the 2824-2, and the base that luxury brands chose when they didn't make their own. That's why you'll rarely see "2892" on a dial or caseback. Omega calls its versions the 1120 and 2500, IWC the 30110, Cartier the 049, and Longines the L619. Many chronographs, GMTs and moonphases are also built on it with add-on modules.

Specs at a glance

History and where it came from

The first 2892 appeared in 1975, a date version of ETA's thin calibre 2890 at 28 mm across. In 1983 the 2892-2 shrank it to 25.6 mm to match the 2824, but Monochrome's history notes that the smaller rotor didn't always keep the spring full in daily wear. The 2892-A2 of the mid-1990s fixed that with a heavier-edged rotor and lower-friction winding, and that's the version most people mean by "2892".

At 3.6 mm tall it's a millimetre thinner than a 2824, which made it the natural base for elegant watches and for adding modules. Omega used it across the Seamaster, Constellation and early co-axial range. Breitling built many of its chronographs on it with Dubois-Depraz modules. IWC, Cartier, Longines, Hublot, Tudor and Hamilton all used it too, usually under their own calibre names.

ETA stopped supplying outside customers in 2021. Sellita's SW300 is the main replacement for independent brands, and inside Swatch Group the family lives on in longer-running descendants such as Longines' 72-hour L888.

Accuracy in the real world

This is where the 2892 earns its reputation. It was the default base for chronometers in the 1990s and 2000s, and brands that paid for top or chronometer grade got excellent results. Omega's 1120 is COSC-certified to -4/+6 s/day, and Caliber Corner notes that these Seamasters are still accurate decades on when serviced.

Even the Elaboré grade, as in the Hamilton Intra-Matic, is rated at ±5 s/day on average, a tighter spec than a standard 2824. Owners on watch forums commonly report single-digit daily rates. Like any movement, rate can wander as the spring runs down, so a 2892 that's nearly empty on a Sunday is less accurate than one worn daily.

Reliability and servicing

The 2892-A2 is well proven, with no known systemic weakness. It's a slightly more delicate, finer-built movement than the 2824, and watchmakers treat it that way.

• Brand service. Omega, IWC and Cartier service their own versions and may replace parts with their own specifications.
• Independents. Any competent watchmaker knows the 2892, but genuine parts are more tightly controlled than for a 2824. A modified version such as the Omega 2500 co-axial needs brand parts.
• Interval. About five years is typical, sooner if the reserve or accuracy drops.

Quirks worth knowing

• Brand names hide it. An Omega 1120, IWC 30110, Cartier 049 or Longines L619.2 is a 2892 underneath. Check the calibre number, not just the brand.
• Early 2892-2s wind less efficiently. If you buy an older 2892-2 watch from the 1980s or early 1990s, expect it to need more wear or occasional hand-winding.
• Date danger zone. Don't quickset the date between about 9pm and 3am. Here's why.
• Thin can mean fragile. Watchmakers generally advise gentle hand-winding. A few turns to start it, then let the rotor do the work.

How it compares

• ETA 2824-2: the same footprint, about a millimetre thicker and a few hours shorter on reserve. Cheaper, tougher and easier to service; the 2892 is finer and slimmer.
• ETA 2893-2: the GMT version of the 2892, with a 24-hour hand.
• Sellita SW300: the modern equivalent, with 56 hours of reserve in current versions.
• Longines L888: the 72-hour descendant with a silicon balance spring.
• Omega 8800: what replaced it in modern Omegas, with a co-axial escapement and 55 hours.

Living with the 42-hour reserve

Forty-two hours is almost a weekend, but not quite. Take your Seamaster 300M off at 6pm on Friday and, from full, it stops around noon on Sunday. A dress watch like the Jazzmaster Thinline or a Cartier Ballon Bleu that only comes out for occasions will nearly always be stopped when you reach for it.

If you rotate watches, wear the 2892 first after a break, or give the crown a couple of dozen turns the night before a Monday. Watch Winder counts down the 42-hour reserve for each watch you own and reminds you before it stops. To check a particular weekend, try the "Will my watch stop?" calculator.

Verdict

The ETA 2892-A2 is one of the best mass-produced automatics ever made: thin, accurate and adaptable enough to sit under dozens of luxury calibre names. It's a big part of why a used 1990s Seamaster 300M or an IWC Mark XVII is such a safe buy, and why the Hamilton Intra-Matic 38 punched above its price. The downsides are a reserve that won't survive a full weekend and servicing that's slightly more specialised than a 2824's. If you find one in a watch you like, it's a mark of quality.

FAQ

How long does an Omega Seamaster 300M run off the wrist?

The 1990s Seamaster Professional 300M uses Omega's calibre 1120, based on the ETA 2892-A2, which runs for about 42 hours from full. Newer Seamasters with Omega's 8800 series run longer.

What movement is in the IWC Mark XVII?

IWC calibre 30110, which is based on the ETA 2892-A2. It beats at 4 Hz and runs for about 42 hours from a full wind.

Why did my Hamilton Intra-Matic stop over the weekend?

The 38 mm and 42 mm Intra-Matic use the ETA 2892-A2, which runs for about 42 hours from full. Two days in a drawer is usually enough to stop it.

What movement is in the Cartier Ballon Bleu automatic?

Many Ballon Bleu automatics use Cartier's calibre 049, which is based on the ETA 2892-A2. Newer models may use Cartier's own calibres, so check your reference.

How accurate is the ETA 2892-A2?

Elaboré grade is rated at about ±5 seconds a day on average, top grade ±4, and COSC versions such as the Omega 1120 at -4 to +6. Many owners report a few seconds a day once serviced.

Is the ETA 2892 better than the 2824?

It is thinner, better finished and typically more accurate at the same grade, with a slightly longer 42-hour reserve. The 2824 is tougher, cheaper and easier to service.

Does the ETA 2892-A2 hack and hand-wind?

Yes. Pulling the crown to set the time stops the seconds hand, and the movement can be wound by hand through the crown.

Sources

• Monochrome: The history of the 2892, ETA's enduring elite movement
• Caliber Corner: ETA Caliber 2892-A2
• Caliber Corner: Omega Caliber 1120

Watches we've reviewed with the ETA 2892-A2

• Hamilton American Classic Intra-Matic Auto review
• Hamilton Jazzmaster Auto review (Viewmatic, Performer and Thinline)

Keeping it running

• On an average day an automatic gains roughly 4 hours of reserve per hour on the wrist, so about 10 hours of wear fills the ETA 2892-A2. Desk days charge more slowly.
• Most automatics can also be wound by the crown. If yours has stopped, a few dozen turns gets it going before you put it on.
• Off the wrist it stops about 42 hours after it was last full. Stopped sooner?
• On a watch winder, start at about 650 turns per day, both directions. Winder settings for every movement.
• If it does stop, don't set the date between 9pm and 3am. Check if it's safe.

All ETA movements

Never let it stop

Watch Winder counts down the reserve of every watch you own and reminds you before one stops. It already knows the ETA 2892-A2: type your watch's name and the reserve fills itself in.

Manufacturer's published figure. Real reserve varies with the watch's age and service; check your manual.