RavTech(TM) 7 Colors Changing Glow LED Light Water Stream Faucet Tap This little device fits on most taps and lights up its LED when you turn on the tap. ABS electrochromism material, excellent corrosion resistance, durable. The light is activated by water pressure and turns off automatically with the water. Colors are mixed displayed automatically when water flow (the light colors are NOT affected by water temperature). Transforming the stream of water into a beautiful waterfall of light.