A:Answer Hi Benny,
Thank you for your question.
1.If you do not use a doorbell chime, you MUST use a 20 ohm/10 watt resistor between the smart doorbell and one wire from the power source. Please note that resistor not included in packaging.
2. When the visitor press the button, the doorbell WILL play a tone (Like the normal mechanical doorbell) for the visitor. And you will receive a notification via the app.
Hope this will help.
Best,
Zmodo Support