When a visitor presses the call button on dbell wireless smart video doorbell, a chime will ring inside the home and associated smartphone or tablet will simultaneously ring or receive an alert that somebody is at the door. If you answer the alert/ring, doorbell will send a live audio and video feed to the smartphone or tablet from the doorbell. You will be able to see, hear and talk to the visitor at your door No matter where you are. You can be anywhere in the World, your phone needs to be within the Cellular or Wi-Fi Network coverage area. Special benefit is thatÂ even if your APP is not runningÂ you will get an alert. The whole idea of this new technology is providing convenience for elderly and disabled. Providing safety to the Women and Children, providing security at your doorstep, giving freedom at your fingertips. It is a DIY product. User can easily install this product using existing doorbell power cable. Ability to use existing cable minimizes the amount of installation time and save money to enjoy this great new technology. Power requirement is 12~24VAC or 12VDC, 0.5A Also, a door chime inside your home connects wirelessly to the doorbell. You can have as many door chimes as you want. Doorbell communicates with door chime via radio frequency, so range is excellent. Door chime rings when the doorbell call button is pressed.