After adding a custom hang-on-back riparium to my freshwater aquarium I added this rather than replace my existing in-tank heater with something bigger. So far it works perfectly.

nice simple product

I use 5 of these heaters for my plankton reactors and they all do perfectly their job. Easy to clean.

Good wee heater, but the one I got is like the "Aqua Syncro MH Heater", flat and flexible.