The all new Cobalt Aquatics NEO - Therm fully submersible electronic heaters feature a modern, super flat design with an easy to set "one touch" control system. The advanced electronic thermostat is accurate to ±0.5oF and includes a LED that displays both the Set Temp and Tank Temp simultaneously and has a Set temperature range from 66oFup to 96oF. For ultimate safety and reliability, integrated thermal protection circuitry shut the heater down before it can overheat and its shatterproof outer casing make the NEO - therms virtually indestructible. Perfect for freshwater and saltwater aquariums and terrariums. Features Correct heater postion - Vertical with heating element down, bezel, cord and button up. Minimum water level - Top of the bezel. For 25, 50, 75watt 5.5 in. from bottom of the heater. For 100 watt 8.75 in. from bottom of the heater. Maximum depth of 31.5 in. deep at the bezel Model - 150 W Aquariums Up To - 40 Gallon Size - 3.25 L x 2.25 W x 11.75 H in. Item Weight - 0.88 lbs.