5 minutes

ETA and Sellita – More Than Off-The-Shelf Movements

By Tim Breining

Everyone’s heard of movements like the ETA 2824-2, Valjoux 7750, and, increasingly, their counterparts from Sellita. All of these calibers are considered proven, high-quality workhorses. For a long time, buying calibers from these market-dominating movement suppliers was the only option for medium-sized watch brands. However, the trend toward in-house movements – whatever that term truly means – is a force to be reckoned with. On the one hand, it has promoted vertical integration for many watch manufacturers. On the other, it’s opened up the market for new movement suppliers to establish themselves. What these newer movements lack in terms of proven reliability, they often make up for with innovative designs and generous power reserves.

But anyone who thinks the top dogs on the movement market don’t have anything interesting left up their sleeves doesn’t know their full range of products. Both ETA and Sellita have some hidden gems on offer that fly under the radar of many watch enthusiasts but are definitely worth a closer look.

1. ETA A31

ETA’s Powermatic 80 series, which is based on the 2824-2, has been powering watches from brands in the Swatch Group for many years now. The group brands have a distinct advantage over external parties, who have to make do with the historical models. You can learn about the history of these movements in more detail in this article.

In that article, I suggested an alternative caliber for those who aren’t fond of the various Powermatic 80s due to the significantly reduced frequency and, in some cases, the plastic escapement components. The alternative I gave is the ETA A31 series, which is based on the ETA 2892-A2. Since the 2892-A2 is both slimmer and of a higher quality than the 2824-2, you could call the A31 series a premium upgrade to the classic Powermatic.

In contrast to the Powermatic 80, ETA took a bit more care when adapting the original 2892-A2. The biggest point of criticism for the Powermatic 80 is, of course, the reduction in frequency from 4 Hz to 3 Hz. This is more modest with the A31, which has a balance frequency of 3.5 Hz, down from 4 Hz. Thus, the second hand is only slightly more jerky. That being said, the caliber only has a 65-hour power reserve as opposed to 80 hours.

The escapement of this movement is equipped with a silicon hairspring – searching for plastic components will be in vain. The upgrade is also exceptionally slim. The combination of these attractive characteristics makes the A31 the chosen one among the Swatch Group’s “middle class” brands. The series is predominantly used to power watches from Longines and Union Glashütte, where it is known as the L888 and UNG-07.01, respectively. With the A31.L21, ETA even offers a modular chronograph movement with a bicompax layout; the base movement is outfitted with ETA’s own module. You can find this rare caliber in the Longines Heritage Classic Tuxedo chronograph, a successful remake of a model from 1943.

The Longines Legend Diver with an ETA A31 movement

2. ETA L668

In 2005, ETA introduced a new series of movements called the “Valgranges.” These were primarily larger versions of the tried-and-tested Valjoux chronograph caliber. At the time, watches with diameters well over 40 mm were on trend, and viewing smaller movements through display case backs was getting borderline ridiculous. ETA already had a proven solution for hand-wound models in the Unitas 6497. For chronographs, however, petite calibers meant unbalanced dials with subdials and date windows crammed together unnecessarily at the center, while the edges remained suspiciously empty.

The XL Valjoux calibers didn’t exactly manifest a brilliant technological revolution, but they certainly met the functional and aesthetic needs of the time. There was, however, a somewhat revolutionary movement tucked away in the Valgranges range: the L668.2. This vague designation belongs to a variant of the Valjoux 7753 movement (with subdials at 3, 6, and 9 o’clock) that was initially specially reworked for Longines.

It’s not just the minor details that were altered on this movement, but rather the very heart of the chronograph mechanism. While Valjoux chronographs are generally cam actuated, this movement relies on the coveted column wheel mechanism. The oscillating pinion was retained as a coupling mechanism, which means the L688.2 doesn’t have to rely on a vertical clutch + column wheel, which is often touted as the “ideal” pairing. There’s no doubt this came down to the fact that they were working within the confines of an existing movement. In any case, given the features of this movement and the moderate prices for the watches it powers, this is definitely an insider tip! In addition to being used in Longines models, it was also equipped with a co-axial escapement, designated the caliber 3330, and fitted in certain Omega models until 2014.

Even Omega turned to a modified version of the ETA L668

3. Sellita SW 266

The SW 266 isn’t listed in Sellita’s online catalog, but we know the brands that rely on it. There seems to be just two at the moment: the Swiss brand Louis Erard, which is known for its extraordinary design collabs, and the German brand Zeppelin. The regulator is Louis Erard’s trademark, thus, it shouldn’t come as much of a surprise that the Sellita SW 266 is specially designed for regulator watches. This means that all the hands lie on the central vertical axis of the dial, with just the minute hand at the center reaching the dial’s edge. The hour and second hands, in turn, are located at 12 and 6 o’clock on smaller subdials.

Manufacturers previously had to redesign movements or add modules to achieve this characteristic arrangement. With the SW 266, however, Sellita has offered a ready-made solution for a number of years now.

This movement from Sellita’s SW 200 series, like the classic ETA 2824-2 on which it is based, doesn’t stand out with any exceptional performance figures, but it doesn’t have to. It perfectly fulfills its purpose of supplying regulators with a ready-to-go movement.

The Sellita SW 266 in the Louis Erard Excellence Régulateur Malachite

4. Sellita SW 1000

Unlike the vast majority of Sellita’s range, the SW 1000 isn’t based on a historic ETA movement, but instead is an in-house development from the 2010s. Due to its compactness, it is perfectly suited for modestly-sized women’s watches or men’s watches with unusually shaped cases.

Measuring just 20 mm across, it comes in almost 6 mm smaller than ETA’s Powermatic 80 or 2824-2 movements. It is still larger than the 17.2-mm SW 100, however, which itself is a copy of the ETA 2671. That being said, the SW 1000 is significantly slimmer, standing just 3.9 mm tall compared to the SW 100’s 4.8 mm. Sellita describes the SW 1000 as a “small counterpart to the SW 300,” which itself is a clone of the ETA 2892-A2. Therefore, the SW 100 and SW 1000 can be compared to the 2824-2 and 2892-A2: The former is inexpensive and reliable, while the latter is high-quality and exceptionally slim.

A TAG Heuer with the Sellita SW 1000

The most notable customer for this movement is probably TAG Heuer, where the SW 1000 powers automatic women’s watches and is referred to as the caliber 9.

About the Author

Tim Breining

My interest in watches first emerged in 2014 while I was studying engineering in Karlsruhe, Germany. My initial curiosity quickly evolved into a full-blown passion. Since …

Read more

Latest Articles

Watch Technology
 6 minutes

The Chrono24 Watch Collection – Where Your Watches Are Right At Home

By Pascal Gehrlein
Watch Technology
 6 minutes

Three of the Rarest Complications: Function, Purposiveness, and Play

By Tim Breining
Watch Technology
 5 minutes

The History and Evolution of the Chronograph

By Aaron Voyles


 5 minutes

The Best for $24,000: Donato’s Perfect 2024 Watch Collection

By Donato Emilio Andrioli
Top 10 Watches
 5 minutes

10 Best Watches Under $2,000

By Donato Emilio Andrioli
Jorg’s $24,000 Watch Collection
 4 minutes

The Best for $24,000 in 2024: Jorg’s Perfect Watch Collection

By Jorg Weppelink
Top 10 Watches
 5 minutes

10 Best Watches Under $2,000

By Donato Emilio Andrioli