AquaEl Flow In-Line Heater 500 The AquaEl Flow In-Line Heater 500 is the first heater on the market that uses the Smart Heating System or SHS for short. This means that it is capable of using its onboard micro-processor to adjust the heating power to maintain a specific desired temperature in the aquarium. The display on the heater will show both your target and the current temperature that it currently stands at which means this system is a thermometer and a heater in one. Alongside this, the electronic temperature sensor stops the aquarium overheating and will automatically switch off the heater if flow comes to a holt from filter failure or accidental disconnection from the flow. This will protect the device from overheating while exposed to the air, a very common failure point in most aquarium heaters. Another bonus of this heater is the ability to hide it out of sight! Being an In-Line heater, you can place this on the outlet of your filter in any position to keep it hidden. It also has the benefit of not being in the tank because it is In-Line. As a result, you can enjoy an uninterrupted viewing experience in your main display. This heater features a high-precision thermostat which gives a +/- 0.5 accuracy within a range of 20-33 degree Celsius making this one of the most accurate heaters available right now. It can also be used on both saltwater and freshwater systems making it even more versatile and showing resistance to harsh water. At a glance For 16/22mm hosing, making it suitable for most external filters. Uses the new SHS technology. 0.5 accuracy within a 20-33 degree Celsius. Can be used on Freshwater and Saltwater systems. Triple temperature sensor, 2 electronic and 1 thermal fuse. Suitable for 300-1000L Aquariums.