Light-Up Faucet has mini built-in electricity generator to light up in different colors as long as the water is running. Therefore, you'll NEVER need batteries. The light turns off immediately when the water is turned off.
*Universally fits on all faucets
Blue - Water temperature is below 32 degrees
Green- Water temperature is between 33 to 41 degrees
Red- Water temperature is between 42 to 45 degrees
FlashingRed- Water temperature is higher than 46 degrees
Internal diameter: 0.6 inch External thread diameter: 0.86 inch Item size: 1.4 * 0.95 * 0.95 inch