The heater is the Fluval E Series VueTech one. It comes built in to that grey filter guard, and has an LCD display for you to keep track of the temperature. You can digitally set the temperature required to within 0.5 degrees, then if it gets more than a degree or so low it blue, a degree or two hot and it goes red, and green means it's ok. If it goes red or blue and flashes, it means the temp is opver 3 degrees out.
Great heater. My old one just had a plus and minus sign and decided to become oblivious to me trying to change it. I still keep a separate thermometer in the tank as a check, but they both read pretty close to the same reading. Not the cheapest, but worth the cash in my eyes.