Review on 🐠 PGFUNNY 25W Aquarium Heater, Smart Thermostat Fish Tank Heater for Betta, Slim Design Fits 3 to 5 Gallon Tanks, with Thermometer Strips by Andrea Young

The product is supplied pre-assembled and is easy to attach to the aquarium with or without water. It gradually warms up my 2.5-3 gallon tank, which is best for fish, and the thermometer mounted on the opposite side reads very clearly. The red light indicates whether the heater is active. Sometimes I do a partial tank cleaning and try to remove the heater, the bottom suction cup stays attached to the tank while the heater slides out, but that's a minor inconvenience, not worth removing the star. My betta even liked to use the heater as a resting place. The cord is only a few feet long, so you must be near a power source. It's unobtrusive. My only complaint would be that the instructions were minimal and not in English. The drawings were simple enough to get the point across, but it would be helpful to add a few sentences to make sure I got the installation process right.