Water Filter for Sink Faucet, NSF Certified Faucet Mount Water Filtration System with UV Light and Real-Time Filter Life Indicator, Reduces Lead Chlorine, Heavy Metals (Incl. 1 Filter, 13 adaptors)Patented Turbine Hydropower Technology: Our faucet water filter features patented turbine hydropower technology, eliminating the need for electrical power or battery charging. This innovative system generates energy from water flow, ensuring continuous and efficient operation without external power sources. The UV light and LED display are driven by this hydroelectric power system. When switch to filtering mode, the blue light and LED screen are on.