This is a very simple pedal in that it just flips between to jacks. I would guess it is most often used for switching between 2 different amps, but I wanted to switch between two different guitars as input. No need to pull cables, just switch guitar and hit the stomp. So I use it "upside down".
With power, you get an LED with different color to indicate which channel you are on.
It does not take battery, but the functionality is just the same regardless. It is just about the LED being on or not.
Needless to say, for me it is an "always on" pedal.
Pros:
Does its job flawlessly
Totally silent
Small so it does not take much space from the board
Cons:
(None)