The Exacta has 2 clocks: a big clock and a kitchen clock. The kitchen clock is set and rings at the end. For example, you can set the baking time for a cake. When the timer rings, the cake is ready and must be taken out of the oven.
The Exacta was made of pottery. That's why the Exacta was washable. The Exacta quickly became a classic. Max Bill designed the Exacta. Max Bill was the director of the Hochschule für Gestaltung in Ulm. At the Hochschule für Gestaltung people study what objects look like. The Junghans company said to Max Bill: Please make clocks for the kitchens of the 1950s.