Anself Temperature Sensor Water Glow LED Faucet Stream Light 3-color Green Red Blue This little device fits on most taps and lights up a set of LEDs when you turn on the tap. Transforming the stream of water into a beautiful waterfall of light. The sensitive faucet light will change colors according to the temperature of water. The color's change remind you the water's temperature. No batteries and external power supply, it will illuminate after water flows down.