The Manufacturer Informs : 

The external FLOW HEATER is used to heat water in freshwater, marine and aquaterraria. It is designed for installation on pipes with a diameter of 16/22 mm and a maximum pressure of 0.03 MPa. It has a precise, fully electronic thermostat and a thermal safety switch.

The heater has been equipped with an intelligent system for selecting the optimal power output. Depending on the room temperature and the set temperature, the microprocessor-based system selects the minimum heating power required to maintain the set temperature. If necessary, the microprocessor increases or decreases the power to maintain the set temperature. Thanks to this solution, the processor selects the appropriate power without the need for user intervention. This means that it can operate in an aquarium of virtually any capacity (up to about 500-1000 l depending on the conditions in the room).

The first intelligent outdoor heater
Equipped with Smart Heating System: adjusts the heating power according to the size of the pool and environmental conditions, using only the amount of energy strictly necessary
It is equipped with a precision electronic thermostat, operating with an accuracy of ± 0.5°C, over a temperature range of 20 to 33°C
You can conveniently set the temperature with just one button: One Touch System
LED display shows programmed and current temperature
3 temperature sensors - 2 electronic, 1 thermal fuse
The heater automatically switches off if the water flow stops
For 16 / 22 mm diameter tubes in freshwater and marine aquaria