Fluval T Series submersible heaters combine electronic accuracy, reliable monitoring, and multiple safety features to easily maintain desired aquarium water temperatures. The 360indicator light ring displays heat mode clearly from any angle, while a convenient large grip dial allows users to adjust the water temperature with ease. In absence of water, the Fluval T Heater automatically cuts power to prevent overheating, while a heater guard provides additional peace-of-mind protection.Fluval Aquarium Heater T Series+ advanced electronic construction provides superior accuracy, stability and long-term performance+ 24/7 monitoring regulates temperature and avoids large, unsafe fluctuations+ 360indicator light ring displays heat mode clearly from any angle+ illuminates RED when heating function is engaged and BLUE when desired temperature is achieved+ in absence of water, the T-Heater automatically cuts power to prevent overheating+ heater Guard provides additional protection against b