Self-Powered Doorbell Smart Waterproof Electronic Doorbell Main Feature 1. Self-powered outdoor unit, no battery, more environmentally friendly 2. Outdoor unit waterproof design, please note: is PCB plating waterproof membrane, do not peel, PCB board bubble water does not affect the use! Effectively solves problems that can be used normally in rainy days and can also be used in very humid environments 3. The slim design of the outdoor unit can effectively prevent the outdoor unit from being intentionally picked up 4. The indoor and outdoor units are made of ABS material (power is PC fireproof material), and the surface is enamel printed. It is elegant and chic but can also effectively prevent the shell from being affected by beauty after a slight cost-effective 5. Eye-catching backlight flashes when someone presses the doorbell. especially suitable for the elderly, deaf, and pregnant women 6. If paired with multiple push units in one system, the ringtone can be set individually for each push unit 7. Automatically saves the selected ringtone after power off 8.Flexible design, easy to install, no wiring required, money and labor saving, free movement 9. Electrical voltage reduction, making it safe 10. Mini size and beautiful appearance 11. Built-in stereo speakers, especially suitable for office buildings, households, factories, tourism and other places, a wide range of applications