Sellita · Automatic caliber guide
More room for a slimmer watch.
At 3.60 mm, the SW300-1 is a full millimeter thinner than the SW200-1. That gives a case designer more room to work. Current Sellita documentation also specifies a longer reserve, but the production version and the watch brand’s own specification still matter.
Explore watches using itThe reference card
Published figures, with the context that makes them useful.
Specification reference: Sellita — SW300-1 technical documentation (PDF). These are published specifications, not measurements from my own testing. All manufacturer sources ↓
My take
I would look for a tangible benefit in the complete watch: a slimmer case, a stated longer reserve, or a clearly documented accuracy commitment. Those are useful reasons to consider an SW300-1 watch. The movement name by itself would not persuade me to pay more.
Beyond the spec sheet
Sellita’s current technical document specifies a minimum of 50 hours and a typical 56 hours. Older watch specifications can differ: Typsim’s 2021 brochure, for example, listed 42 hours for its SW300-1 watch. A current document does not change the specification of an older watch; use the reference and production version to establish what you are buying. [source]
The manufacturer lists a date-equipped SW300-1 a and a no-date SW300-1 b. The latter has winding and time-setting positions without a date-correction step. A dial without a date window is not, on its own, proof of which execution sits underneath. [source]
Hand winding and stop-seconds are provided. For a date-equipped watch, follow its manual for quicksetting and the interval to avoid. Case construction, crown position, and a screw-down system can change how the controls feel and how you secure them afterward.
Compare the tradeoffs
Useful comparisons for choosing a watch. These are not claims of parts compatibility.
The movement, in a watch
A selected starting list, grouped by brand. Each exact model below has a manufacturer source confirming the caliber.
Reference 1050.010
Sinn’s current U50 page specifies SW300-1 and a date display. Sinn cautions that older dealer stock can differ from its current production specifications.
Reference C60-42ADA31S0KW3-B0
The white C60 Sapphire Edge on the Bader bracelet explicitly lists SW300-1 and a 56-hour reserve. Check this exact reference rather than another C60 generation.
Model and caliber checked October 14, 2026. Specifications and stock can change; confirm the exact reference with the seller. A manufacturer-verified example is not a hands-on review.
Quick answers
Current Sellita revision 08 gives a 50-hour minimum and 56-hour typical reserve. The 42-hour figure appears in older watch specifications, including Typsim’s 2021 brochure. Confirm the version in the particular watch instead of applying the latest figure to every SW300-1.
No. Sellita lists multiple executions. Only use a chronometer claim when the watch brand supplies the relevant certification information for that reference; the SW300-1 name alone is not certification.
No. Sellita’s catalog distinguishes SW300-1 a with a date from SW300-1 b without one. Check the manufacturer’s description of the exact watch, particularly if you want a no-date crown setting without an unused calendar position.
Check the details
Movement specifications checked . Watch-specific evidence is linked with each example above. I keep manufacturer claims separate from my editorial assessment and any hands-on review.