it is 1000w temperature controller made by Zila http://www.amazon.com/Zilla-Temperat...ure+controller if u go to that link it has the pic of the controller out of the box so u can see the probe , u will see what i mean , the other person that posted said to put the probe under the heat pad, i have been putting in the tank directly over top of the pad . i don't understand why i would put it under the heat pad in not above