C. Stiefelmayer Hand Tachometer with Stop Watch No. 44

This device ensures quick and accurate speed measurement. Turning the knurled button zeros the numbers, winds the clock, and resets the seconds hand, preparing the tachometer with one action. It starts only after a certain pressure is applied and counts forward in both directions. The clock runs for one minute, and the tachometer can be detached before this time, with time and revolutions remaining displayed.