The product buit-in device for mini generating electricity,illuminated by water without battery,the light will go out when the water was turned off.The illuminated colour will change according to the water temperiture. A.Between 0~29℃ , the LED faucet light will emit Green colour;B.Between 30~38℃, the LED faucet light is Blue clour;   C. Above 39℃, the LED faucet light will emit Red colour