I have a few preset heaters for my smaller tanks, and they aren't too bad, as long as I don't need to raise or lower the temp for any reason.
What is that stick man thing in his tank? Is that orange duct tape? Lol
Don't forget a tank hood, if it doesn't come with it, because Bettas can jump out of their tank! I saw that for the first time today during a WC. Luckily she didn't get out of the tank, but I literally took the lid off, and she started jumping...like she had her escape planned haha.