I can't understand why Eheim heaters have such a good reputation. I have three, and none of them are perfect for their price. Generally, I believe they struggle with temperature regulation. Specifically, this one maintains the temperature just fine, but to adjust it, you have to make small tweaks until you get it right. I wanted 25 degrees, and I have it somewhere around 24. And this changes every time I have to unplug it. Also, I want to emphasize that it's not just mine that has a deviation like someone might say 1 degree. I mean, if I want 24, I have to set it to 23 or 26 to get 25. If you adjust it every time, this can change. It also matters whether you adjust it by increasing or decreasing the temperature. For example, if I want 25, I set it to 22 and then see after a while what temperature the aquarium has. I increase it very slightly without looking at the display and observe the aquarium's temperature. I repeat the whole process with fine-tuning until it locks in at the desired 25. If a mistake happens and I raise it too much and it exceeds 25 and I need to lower it, then everything changes. For instance, if during the increase to 23.5, it registers 24.6 and I set it to 24 and it registers 25.5, if I lower it back to 23.5, it won't register 24.6 but might register 25.2. In general, adjusting it for a stable and desired temperature is incredibly difficult. I use the above as an example and not that I am looking for and striving for such absolute temperature. I want to quickly and easily set a temperature and get approximately the desired one, in my case around 25. Not to set 24 and have it register 26-26.5, and with a slight turn, it's 25, and for that point to change and depend on the turn for decreasing or increasing the temperature. I emphasize again that I have 3 that do this, but 2 are the Jager, where things are worse.

Excellent. I needed to buy it because the 50w I had struggled to reach 22 degrees. This one reached the temperature I set with precision, speed, and stability in a 60-liter aquarium.

It does what it promises. Sturdy construction and easy to use. I use it in a 70L aquarium, the temperature stays stable at 27 - 27.5 °C, in a workspace that is not constantly heated!