No battery needed; Visually displays current water temperature; LED color changes according to water temperature. LED light is activated when the faucet senses water flow. Mode: Green: <= 31'C; Blue: 32'C~43'C; Red: 44'C~50'C. When the water>50'C, be careful to avoid being burned, red flashing prompt. Service lifetime: > 6000 hours. Environmental friendly and energy saving. Stylish and durable, Easy installation. Clean the surface regularly with water and wipe with a soft cloth. For difficult stains or spots, use a mild detergent or colorless glass cleaner. Give yourself a gift with this stylish shower head, and to give your bathroom decor a modern update. Note: The hand shower product is selling without showerhead arm and without Shower Hose Included, without Shower Holder.