Simple ideas often are the best ones, for example, the aquarium heater as a rod. The heating rod is simply hung in the water and heats it. It's true that principle is still the same as decades ago, but a lot has changed in the meantime. Today the JÃƒGER aquarium heater is an ultra-modern thermal device using the best available technology. Now - with in its new jacket of laboratory glass - it offers another an extra quality dimension.