Sellita · Switzerland · Elaboré, Top, Chronometer
Sellita SW300-1
The SW300-1 is the second generation of Sellita's SW300 caliber family, engineered as a direct drop-in alternative to the ETA 2892-A2—a movement ETA introduced in the mid-1990s that became the standard for higher-end Swiss automatic watches. The SW300-1 improves on that architecture in one notable respect: it uses 25 jewels instead of the 2892-A2's 21, with the extra jewels added at the barrel arbour to reduce friction.
The SW300-1 grew in prominence as ETA progressively restricted outside sales of the 2892-A2. It ships in two primary sub-variants: SW300-1 a, which includes a quickset date at 3 o'clock, and SW300-1 b, a cleaner no-date version. A sister caliber, the SW330-1, extends the family to include a central GMT hand.
In 2021, Sellita retrofitted the entire SW300 family with a new barrel and mainspring assembly, extending power reserve from 42 to 56 hours—eclipsing the ETA 2892-A2 on that specification. The current Sellita SW300-1 technical documentation lists three accuracy ranges: Elaboré, Top, and Chronometer/COSC. Elaboré is specified at a 5 ±5 s/day middle rate with 20 s/day maximum divergence; Top is specified at a 4 ±4 s/day middle rate with 15 s/day maximum divergence; Chronometer is specified to COSC criteria. The current Sellita SW300-1 documentation lists Incabloc shock protection across its documented Elaboré, Top, and Chronometer ranges.
Hz
Jewels
Reserve
In catalog
Technical specification
| Manufacturer | Sellita |
| Origin | Switzerland |
| Type | Automatic |
| Beat rate | 28,800 bph · 4 Hz |
| Jewels | 25 |
| Power reserve | 56 h |
| Diameter | 25.6 mm |
| Height | 3.6 mm |
| Hacking seconds | Yes |
| Hand-winding | Yes |
| Date | Yes |
| GMT | No |
| Chronograph | No |
| Accuracy (stated) | Elaboré: middle rate 5 ±5 s/day, max divergence 20 s/day; Top: middle rate 4 ±4 s/day, max divergence 15 s/day; Chronometer: COSC criteria |
| Based on | ETA 2892-A2 |
3 models
Watches with this caliber
FAQ
Is the Sellita SW300-1 automatic or manual?
The Sellita SW300-1 is an automatic (self-winding) movement: a rotor winds the mainspring from the motion of your wrist, so it needs no battery. It can also be wound by hand via the crown.
What is the power reserve of the Sellita SW300-1?
About 56 hours on a full wind — into a second day, so it keeps running overnight off the wrist. Power reserve is how long the Sellita SW300-1 keeps running once you stop wearing or winding it.
Does the Sellita SW300-1 hack (stop the seconds when you set it)?
Yes. Pulling the crown stops the seconds hand, so the Sellita SW300-1 can be set precisely to a reference time before you push the crown back in. Hacking is what lets you sync several watches — or a watch and a phone — to the exact second.
Does the Sellita SW300-1 have a date function?
Yes — the Sellita SW300-1 can drive a date display, though whether a given watch actually shows the date depends on the dial the maker chose, so check the individual model rather than the movement.
How accurate is the Sellita SW300-1?
The Sellita SW300-1 is rated at Elaboré: middle rate 5 ±5 s/day, max divergence 20 s/day; Top: middle rate 4 ±4 s/day, max divergence 15 s/day; Chronometer: COSC criteria. That is a normal working range for an uncertified mechanical movement; a COSC-certified chronometer is held to a tighter −4/+6 s/day, and a watchmaker can usually regulate one closer. Real-world accuracy still depends on how each watch is regulated, worn, and serviced.
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