No batteries and external power supply、 it will illuminate after water flows down.Automatic light switching.7 color are displayed automatically when water flow.Main colors are Green、 Red Blue.LED Emitting Color: green、 blue、 red、 etcABS electronickelling material、 excellent corrosion resistance、 durable.Transforming the stream of water into a beautiful waterfall of light.Brightness is such enough even no other lighting fixtures need.Fits all standard connectors、 easy to install.Offer you a delight bath a wonderful experience.Ideal for bathroom to make it more fantastic.The change of LED color will not be subject to the temperature of water. SHAZIXIUTAO XIAOWEI