Water powered - No charging. No batteries. No caps. This smart light attaches to your faucet and creates its own power from the water flowing through it. It's your very own little hydroelectric power generator that creates a colorful waterfall every time you use it. Fits standard easy-to-install threads - If your faucet has a standard round thread ( female or male), it will work for you. We have included an adapter for male threads. To install, simply take it out of the box, remove your existing cap, and screw it into place. Great for Families, Kids - Whether you're using it in a classroom, a kitchen or a bathroom, it is sure to make an impression. The colors are vivid and change depending on the temperature of the water passing through it. Perfect as a safety measure for small children and babies. Great gift for boys and girls. Safe and Durable - Made of ABS (like LEGO) and other high quality materials, this light will not rust or corrode. Electrical components are neatly and securely separated from parts that touch water and the LEDs are rated to last 50,000 hours. Warm Warning: If the LED water faucet lights up, it requires a certain water pressure. And it won't turn on if the water pressure is too low. The faucet is made of ABS, so it is recommended to wrap PTFE tape on the threads when installing the faucet. Be careful not to force too much when installing. (ABS material breaks easily if you force too much.) 2.8*2.8*3.5cm