This one is the only heater I find on Amazon at 4 1/2 stars. Almost every other one has had complaints of them frying their fish or low life expectancy. This one is pricey, yes...about 40 bucks..(for 50 watts. All I need for 10 gallons).but I am considering it for no worry performance. (Its still on my wish list for a tank I am building). I meant the Cobalt you showed.