Watch with a quartz chronograph movement. The top pusher will activate the big seconds hand and the 9:00 subdial is the running seconds for the watch. The bottom pusher will reset the large seconds hand back to “zero”.
The 3:00 subdial is simply a 24 hour indicator that makes a full rotation in a 24 hr period.
Max Bill’s are a beautiful, simplistic watch. I have both this model and the Chronoscope. Enjoy!