A fully submersible aquarium heater, the Newa Therm Pro 250W is fantastic for aquariums up to 300 litres. This exceptionally accurate heater has a micro-processor to electronically control the heating elements and in turn the water temperature. With high mechanical and thermal resistance the heater is virtually unbreakable making it perfect for most demanding fish tanks and fish keepers. With a handy LED which shows when the heater has reached the set temperature, making it even easier to ensure your aquarium is at the perfect temperature. The thermal shock-resistant quartz tube and mechanical tube offer superb protection. Features: Up to 26C. Temperature indicator for temperature setting. Diagnostics feature: RED for heating and GREEN when temperature is reached. Automatic switch-off and re-start, if operated in dry conditions. Exceptional resistance, virtually unbreakable. Thermo cut out if temperature spikes. Length 380mm Diameter 22mm