It was a patented movement, based on a mundane Landeron chrono movement, where Prof. Schaldenbrand added only 12 or so more parts to make a split second chrono out of it.
Starting (with a bit of a jump) is done with the pusher at two, splitting by pushing and holding it pushed with the pusher in the crown.
If you release that pusher again, both second hands catch up again.
To me it is a fun watch with a good history and cheap as chips!
Edo was a brand that used that movement at an early stage.
Regarding my diet regime: seven more kilos to go ๐โโ๏ธ๐โโ๏ธ๐โโ๏ธ