Today’s invention is a novel beard trimmer.
A wristwatch has hands which have sharp edges. The watch glass has radial slots cut through it.
If you want to trim your beard, press the hair up against the glass, so that some hair pokes through.
Now, activate the separate watch motor, so that the hands race around at 100 times normal speed. The hands thus cut off protruding hair, which can be shaken back out through the gaps.
After use, the watch remembers what the time was and resets itself.