【Newly Upgraded Quality】Two super-tough heating tubes are made of explosion-proof quartz glass and high-temperature-resistant nickel-chrome heating wires, distributing heat evenly and heating water faster. The shell is made of V0-rated flame retardant plastic which is corrosion and heat-resistant and prevents fish from touching the heater, thus preventing them from getting burned. (Tips: the plugs on our heater are suitable for Australian sockets, voltage 100-240V). 【Multiple Security Protection】When the water temperature exceeds 94°F or the top of the submersible aquarium heater is 2 inches above the water surface, the heater will automatically cut off the power and stop heating, it will display an error code and sound an alarm until the water temperature is below 94°F or the submersible fish tank heater is completely submerged in the water. 【External Digital Controller】Adjust the temperature without putting your hand in the water. The LED controller can show the current water temperature, preset temperature, and more warning signs of High temperature/ out of the water. The running red light means the heater is heating, and the running green light means the water temperature has reached the set temperature. 【Precise Control Temperatur】Temperature adjustable range: 63-94℉, hold the "+" and "-" for 5 seconds to switch between ℉ and ℃. Accuracy: ±1°F, the adjustable aquarium heater will stop heating when the temperature reaches the setting and restart when it is lower than the setting. The memory function can automatically retain the previous setting when the adjustable fish tank heater is restarted. 【Wide Range of Applications】1000W aquarium heater for 120-300 gallon tanks, please select the appropriate wattage according to our parameters. This fish tank water heater can be widely used in freshwater and saltwater fish tanks, turtle tanks, and aquariums. You can easily mount the aquarium water heater to the tank wall using the included suction cups to maintain the decoration style of your tank.