Self-powered Doorbell Smart Waterproof Electronic Doorbell Main Function 1. Self-powered outdoor unit, no battery, more environmentally friendly 2. The outdoor unit waterproof design, pay attention: is the PCB plating waterproof membrane, dont shell, 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 highly humid environments 3. The slim design of the outdoor unit can effectively prevent the outdoor unit from being maliciously picked 4. The indoor and outdoor units are made of ABS material (power supply pin is PC fireproof material), and the surface is enamel-printed. It is elegant and chic but also can effectively prevent the shell from being affected by the beauty after a slight cost-effective 5. Eye-catching backlight flashes when someone pushed the doorbell.particularly suitable for the elder,deaf and pregnant women 6. If paired with multiple push units in one system, the chime can be set individually for each push unit 7. Automatically saves selected ringtone after powering off 8.Flexible design, easy to install, no wiring required, money-saving and labor-saving, free moving 9. Electric reduction voltage, making it safe 10. Mini size and beautiful appearance 11.Built in stereo speakers, especially suitable for office building, household, factories, tourism and other places, a wide range of uses