Marineland Precision Aquarium Heater, Up to 20 Gallons, 75-Watt

I received the item fast and I am using the Marineland one right now and so far it is working great, but I still haven't received my full refund for the Christmas gift cards that I ordered from Walmart and never received as of yet.

This heater works fine so far, after about a week of use. One thing I don't like is that it uses only suction cups to keep it in place from falling into the water; I imagine the rubber getting brittle after some time, slipping from the glass, and the heater being dunked. Maybe the rubber used nowadays is a newer type that stays flexible permanently. Even so, does the rubber-to-glass seal never get compromised? It would seem more secure if a simple plastic hook were attached to it to hold it in its spot. Other than that, it maintains an even temperature once I set it, and its design and style blend well with the aquarium.