Flip clock in German is Klappzahlenwecker. If it's a rolling wheel flip clock you might call it a Rollzahlenwecker Klappzahlenwecker.
The video below is just a fun look at the "alternate universe of flip clocks" as well as some uncommon makes of flip clocks on eBay.
The video below is just a fun look at the "alternate universe of flip clocks" as well as some uncommon makes of flip clocks on eBay.