1.This product has mini built-in generating electricity devices, no need of batteries, as long as the water flow it will give out light, turn off the water, the light goes out immediately. 2.The product has excellent water conservation function, and connected at the top with the water-saving filter 3.Trouble shooting steps: If The water pressure is too low Clean or replace the aerator If Water is leaking from the faucet under the sink Check the water supply connections to the faucet.If LED does not illuminate check the plug connection. Option Details: red: single color, as long as the water flow it will give out light in Red color, turn off the water, the light goes out immediately. green: single color, as long as the water flow it will give out light in Green color, turn off the water, the light goes out immediately. blue: single color, as long as the water flow it will give out light in Blue color, turn off the water, the light goes out immediately. multi-color: 7 colors, as long as the water flow it will give out light, color will flash and change randomly. temperature-sensor: 3 colors, The color changes according to the water temperature.When the water temperature is below 32 degrees, the light color is blue. When the water temperature is between 33 to 41 degrees, the right shows green. When the water temperature is between 42 to 45 degrees, it will display the red. When the water temperature is higher than 46 degrees, the light flashing red Before buying, Make sure the thread size is M22 1.We will send the items within 3 days(except weekends and national holidays) once your