Feature: 1. PID TEMPERATURE CONTROL: Aquarium heater is made of high temperature resistant ABS housing, which is robust and durable.PID temperature control algorithm, high thermal energy and low power consumption. 2. EXPLOSION PROOF QUARTZ TUBE: Internal with explosion‑proof quartz tube and nichrome heating wire for faster heat conduction and more stable heating to preserve fish, aquatic life and users from scalding. 3. EXTERNAL CONTROLLER: Submersible aquarium heater has an external controller and is equipped with a state of the art heating chip to precisely control the temperature of the aquarium. 4. INTELLIGENT INVERTER TECHNOLOGY: Using intelligent frequency conversion technology, the power size is freely adjusted by the chip, always maintaining a constant temperature at the lowest power. 5. ULTRA SHORT BAR BODY: Submersible fish tank heater features an ultra short rod body, only 23cm long, with an external knob to adjust the temperature for more intuitive control. Specification: Item Type: Aquarium Heater Material: ABS Use: Aquarium Automatic Thermostat Heater Plug Specifications, Voltage: UK Plug, 220V Temperature Control Range: 16-34℃ Length: Approx. 23cm / 9.1in. Package List: 1 x Aquarium Heater2 x Suction Cup1 x Instruction Book Note: Please allow some error due to manual measurement.