Review on Hygger Digital Temperature Controller Aquarium Heater - Shatterproof Titanium Tube, Submersible Fish Tank Heater for 60-180 Gallon Tanks, 500W 800W Power - Ideal for Saltwater and Freshwater by Eric Teofilo

I loved these heater(s) when they first came out, but when they broke the company quickly helped by replacing them. Unfortunately the second failed after the plastic case melted when the water level dropped and the heater wouldn't turn off. The extreme external strength of this device indicates a robust machine. I believe it could be a very good heater in the long run if the manufacturer can fix these little flaws. If so, I would recommend it, but I can't at the moment. The company could not have been more accommodating in replacing the heater without hesitation.