Eth is a heater for aquariums also suitable for sump collection tanks and external filters for vertical positioning only. Accurate thanks to the electronic temperature control, it is specially designed to guarantee high resistance and avoid the risk of overheating thanks to the innovative self-protection ptc heating element, an exclusive archie & oscar technology. Equipped with a special eyelet for fixing, it can be easily connected to pipes or other technical components for aquariums. It is possible to set the temperature between 18° c and 34° c.eth heaters are available in various models with different power and internal tube thickness, they can be combined with the prime external filter by archie & oscar.cleaning tips: periodically clean the heating tube with a soft brush to prevent algae and limestone.