Aqueon Mini Aquarium Heater, 10 Watts, Up to 5 Gallons

Good heater, but it's not accurate. It has no on/off switch and no temperature display as it says it comes preset to 78 degrees F. I bought 3 thermometers, a Taylor that reads 81.7 degrees F and a regular glass thermometer encased in plastic for use in pool water that reads 80 degrees F. and the cheaper stick-on the tank reads 80 and is not made for precision as it only shows temps by twos, 74, 76, 78, 80, 82, kind of useless, lol. So my base is 80 and those 2 degrees matter to my fish. My Betta gets a bit sluggish in anything over 78 degrees F even though I know Bettas can be in up to 85 degrees. But like humans, one size does not fit all and mine is most active when the water is between 76 and 78 degrees F. So I have to unplug the heater and add cool water to bring it down and then monitor it throughout the day until I need to plug the heater back in. I will be looking for another heater but will keep this one as a spare. If I ever upgrade from a 5 gallon tank to a 10, maybe this one would work better? I really like Aqueon products and will continue to purchase them. Thank you.