The MQ Titanium Alloy 200W Aquarium Heater is a durable and reliable heater that is perfect for keeping your fish tank warm. Made of premium titanium alloy, this heater is designed to be resistant to explosions and to withstand harsh conditions. With a wide range of temperatures available, this heater is perfect for many fish tanks. The LED screen makes it easy to adjust the temperature, and the external thermostat controller ensures that the temperature stays constant at the set point. When the water temperature reaches the set point, the heater will shut off, but it will automatically start up again when the water temperature drops below the set point.