This is a replacement mounting bracket for a Fluval aquarium heater. It has two spots to mount suction cups that came with the original bracket. The original bracket had loosened over time and my heater was slipping down into the water. This design will work with any cylindrical heater around 18.5mm diameter. The fit is snug at 18.5mm heater diameter.
I'm suggesting infill at 100% simply because the volume of this print is very small to begin with and printing with less infill isn't going to save much filament.