<br>High-power digital control quartz glass aquarium heater is specially designed for medium and large fish tank use, fast heating up for 30-120 gallon tank <br> <br>We now have 300W and 500W fish tank heaters available. It comes with 1 quartz glass heater, 1 IC temp controller, and 1 thermometer; the cables are all long enough for use indoors. Cautions: < please keep the heater fully under water all the time, the plastic guard will be melted if the heater exposes to the air when it's heating or not cool down. <br>Features : <br>Fast heating and reliable, fully automatic control <br>ABS black plastic heater guard with 2 strong suction cups <br>Suitable for freshwater and saltwater aquarium use <br>The controller with memory functions in case of power-down <br>Durable and explosion-proof quartz glass heater tube <br>Very easy to install and use <br>Automatically stops and restarts heating <br>It will stop heating when the water temp reaches to the set temp. Please note that the water temp may go up 1℉ more because of the waste heat. When the water temp is cool down to 1℉ less than the set temp, the fish tank heater will restart heating.