I thought I was buying a heating pad, basically what you’re buying is a controller that comes with a free heating pad. I can’t believe the price of this, I would expect at least $50. Especially considering that it is for pet use.It is a temperature controller, displays current temp inside tank, and has a separate permanently wired temp sensor that sticks to the inside of the tank with a suction cup. The suction cup works very well, even after repeated removals. The heating pad plugs in separately to a 110v plug on the controller. You can use any 110v device, I would only recommend using a heater or heat lamp though lol. I suppose you could wire it into a stereo, and when the temperature gets above your set point it starts playing Jimi Hendrix. The problem with that, is you then have to figure out whether or not your reptile is more of a country fan, or a rock fan..The heating pad is completely covered with adhesive on one side for sticking to OUTSIDE of the tank.It’s a lot larger than I expected, although I didn’t look too see what size I was buying – I just expected smaller.The instructions say multiple times to place on the outside of the tank, so be aware of that. Also, it is absolutely not supposed to be placed on wood or anything other than glass, according to the instructions, so be aware of that.After reading the instructions, and being aware of that, I decided to just set it under the tank, on top of wood. It wasn’t even real wood. It was crap particle board. Maybe the glue in the particle board increased its thermal properties, but I doubt it. I think it’s more probable that the heating pad doesn’t get hot enough to catch wood on fire.I didn’t stick it to the tank because we are replacing the tank in a month. I then decided to move the tank and stick it to the side of the tank temporarily, so I removed a half inch or so (ended up being about an inch) of the adhesive backing all the way around the edge of the heating pad and stuck it to the glass so that I can remove it, and the rest of the adhesive is unused for the new tank.If this is not an absolute permanent fixture on your tank, I would advise sticking it to the tank using only a little bit of the adhesive (by removing small sections of at the adhesive backing to expose only small areas of adhesive). You will never get this off the tank in reusable condition if you use the entire adhesive sheet. I probably exposed too much adhesive. It’s going to be a pain when I go to remove it. [...]