Review on 🐠 Adjustable Aquarium Heaters - Hitop 50W/100W/300W, Submersible Glass Water Heaters for 5 – 70 Gallon Fish Tanks by Karla Harper

This is exactly what I experienced but I gave it 3 stars. Temperature control is difficult but works, suction cups are weak. Inaccurate temperature reading. Verified in USA on March 1, 2020. Verified Purchase. The temperature seems to be quite stable, but finding the right temperature is very difficult. The temperature in the tank does not match the scale of mine. I had no problems starting until 84. I've had no issues with the suction cups not sticking.