It cost 34.99. And it has a laser pointer. Point the laser on a rock or snail shell and it gives you the temp. The closer you are to what you are shooting, the more accurate it is. But there is a ratio that you can figure the temp from a distance. it will also allow you to turn the laser off and I think get surface temp. I'd rather get a middle tank measurement, so I use the laser. It is great for checking your water change temp. I have been checking everything and everyones temp today. Lol.