The Heater Pack contains a 50watt standard aquarium heater capable of heating the water in any biOrb up to 60 litres. A Heater Stand is also supplied that enables to the heater to be fitted securely onto the curved surface of the biOrb. It is also important to monitor the temperature of the aquarium with a thermometer. An accurate glass thermometer is supplied in the Heater Pack. There is a lead from the Heater which needs to be plugged into mains power and there is a section in all of the biOrb lights which allows the lead to pass out of the biOrb neatly.