The Cobalt Aquatics NEO-THERM PRO fully submersible electronic heaters feature innovative circuitry that constantly varies the power consumption of the heater depending on current tank conditions to maximize performance, energy efficiency, and safety. The advanced electronic thermostat is accurate to ±0.5°F and includes a LED that displays both the Set Temp and Tank Temp simultaneously. The heaters also have automatic shutoff circuitry to prevent overheating and its shatterproof outer casing make the NEO-THERM PRO heaters virtually indestructible. Perfect for freshwater and saltwater.