The Fluval E Series Advanced Electronic Heaters are the most technologically advanced aquarium heater available today. Available in 4 sizes; the Fluval 50w, 100w, 200w and 300w Advanced Electronic Heaters, with VueTech technology, deliver peace of mind thanks to several excellent features. Equipped with an intelligent digital microprocessor monitoring system, with dual temperature sensors, the Fluval E Series heaters continuously monitor and display aquarium water temperature, ensuring the safety and well-being of your aquarium inhabitants. Fluval E Series Key Features: Precise Temperature Setting - With the simple adjustment lever the temperature can be set in precise 0.5 Degree increments. Advanced Safety - The integrated fish guard offers advanced protection so the fish and invertebrates do not come into contact with the heater core. Heater Bracket - The heater can be adjusted or extracted without removing the slim mounting bracket. Vuetech Technology - The Fluval E series heaters feature an LCD temperature display that indicates water temperature in either Celsius or Fahrenheit in real time, through a dual microprocessor. The temperature readout will change colour if the aquarium water varies by +/- 1 Degree or more from the pre-set temperature. The screen will flash to indicate potential risk should the aquarium water temperature rise or fall beyond 3 Degrees.