The LED lights in the shower head are powered by the water current and change color to correspond with the temperature of the water. 3 colors will display depending on the water temperature. Temperature sensitive LED shower head provides a visual indication of water temperature. No batteries are necessary and the energy source is strictly from the water current. Its Water flow Approx 2.5 gallons per minute; Colorful rain shower head gets you clean while having fun. Get a clean shower to your own personal light water show with this awesome novelty shower head. Most shower heads just dispense water, this one also provides a nice illuminated shower experience.