The EHEIM thermocontrol E Heater is a precision-engineered submersible heater with a durable laboratory-glass jacket, fully waterproof design, and an integrated dry-run shut-off system. It allows temperature adjustment typically from 18 °C to 34 °C, maintains accuracy within ±0.5 °C, and includes a visible indicator light to show when the unit is heating. This heater is suitable for both freshwater and marine aquariums, and comes in multiple wattage sizes to match tanks ranging from small to large volumes.