The scope works like a reverse periscope – a system of lenses and mirrors give you the feeling that you are observing from inside a mini submersible. Pointing deep into the tank, the periscope lets you inspect your fish at their own level, and a fish feeder has been positioned right by the scope’s lens, so you can watch your fish feed. Use slow gentle movements so you don’t create turbulence in the water and disturb or frighten your fish.