shawn they are used as timers for outside lights ,almost like a chicken coup timer from the old days . they are hard wired as i said so the electrical suppliers would have them . they have their own box like a breaker box but much smaller , say 9"x6"x 5"deep and have a door on the front so you can access them to wire ans to change the timer controlls . i hate the all in one units just cause i have seen a few fires that were caused by them . so far there were people in the house when they decided to malfunction so nobody got hurt just a bit of smoke to contend with .home depot and lowes both carry them and they are found where they sell the electrical outlets ,boxes ,wire,and all that other electrical stuff is but its not like a" plug and play "unit , you would havd a contractor or someone experienced install the unit and run a dedicated line to your aquarium for the lights to plug into .hope i helped to clarify what the heck i meant and good luck and most of all dont be afraid to ask all the questions in the world because the only dumb question is an unasked one .