Esumsky&reg; Temperature Controlled Color Changing LED Light Faucet Tap For Bathroom/Kitchen 8001-A1 Very environmental,no batteries needed,Built-in mini generator powered by water DC current it's only around 3.5v, the water flows and the wires system are separated Lights turns on/off automatically with water flow Temperature sensor controls the LED lights, LED Color: Sensor RGB color changing(blue,green,red) Easy to install and uninstall, great accent for your sink