Sellita Cal. SW500 MP b is an automatic monopusher chronograph movement with date in the Sellita SW500 family. It is based on the ETA 7750 design and shares many components with that movement. Sellita introduced the monopusher MP function in 2018.
This movement features a single button at 2:00 for chronograph start/stop/reset. It has a date window at 3:00, running seconds at 9:00, and a 30 minute chronograph counter at 12:00.
Sellita SW500 and SW600 Technical Information
The Sellita SW500 and SW600 movements are based on the Valjoux 7750 design, itself based on the Valjoux 7733 and Venus 188. This movement is known for durability and flexibility and is used as a base in many watches, from entry-level chronographs to the famous IWC “Il Destriero Scafusia” grande complication. It is a large and relatively thick movement, measuring 13.25 ligne (30.00 mm) in diameter and 7.90 mm thick.
Although based on a classic design, the modern SW500 and SW600 is robust and full-featured. It operates at 4 Hz (28,800 A/h) with an efficient uni-directional central winding rotor. The day and date wheels feature crown-operated quick correction and a stop seconds (“hacking”) feature is included. The base movement has the famous Valjoux 6-9-12 subdial layout with small seconds at 9:00, but many Sellita versions have other subdial designs.
One major differentiator for the Sellita movements is the use of an eccentric screw for regulation rather than the traditional Valjoux articulated index.
Sellita SW500 MP Variants
| Date at 6:00 Chonograph Minutes at 12:00 | Date at 3:00 Chronograph Minutes at 12:00 Small Seconds at 9:00 | Date at 3:00 Small Seconds at 9:00 | |
|---|---|---|---|
 |  |  | |
| No Chronograph Counters | SW500 MP c | ||
| 30 Minute Counter | SW500 MP a | SW500 MP b | |
| 15 Minute Counter | SW501 MP a | SW501 MP b |
