Thumbwheels have been in existence in terms of computers and electronic devices for many decades. They are a precursor to microcontrollers, and as mentioned, they are still quite popular even today. Of course, even before they were useful in electronics, the basic concept of this type of switch was common. Many older locks and suitcases would use a similar system of inputting the right numerical code via a wheel of numbers in order to unlock it. You can see that this mechanical usage of the thumbwheel is still in use as well. Even though it is simple, it works very well.