Get a reostat...........
I would also get a reostat control to plug the mat product into so you can adjust the temperature. Another thing...........be very careful about what is under the mat. What ever surface is under that tank heater, and I do mean what ever surface, will get discolored over time. I had one sitting on a rug. I even had a bath towel folded up underneath it to protect the rug. After a couple of months I moved it to clean it. Not only was the towel discolored permanently, but the rug was too. I couldn't believe it. Prolonged use of a heat product, even a low heat one, will discolor fabric, carpet, rugs, wood, etc.