Usually they're used in thin devices where a bigger battery wouldn't fit. Lots of computer styluses take AAAA batteries, including the Microsoft Surface Pen. There are also some small flashlights and laser pointers that use them.
Usually they're used in thin devices where a bigger battery wouldn't fit. Lots of computer styluses take AAAA batteries, including the Microsoft Surface Pen. There are also some small flashlights and laser pointers that use them.