LED is powered by water flow,no need battery,safe.
3 LED colors will change when water temperature change,you can judge the water temperature according the LED color.
less than 30℃ blue;30℃-40℃ green;40℃-45℃ red;More than 45℃,flashing red LED
Safety first - all bathroom faucet and commercial faucets designed for drinking water use are fully compliant with the latest federal and state lead-free standards