1.4.3” Display: ZEB-VD4 Smart is a video door phone that comes with 11cm display of resolution 480 x 272 for the indoor unit. You don’t have to ask who is outside your door, VD4 Smart shows you who is outside. 2.SOS Alert; VD4 Smart helps you in avoiding strangers from letting in. The indoor unit is equipped with a SOS button. Just a click on the SOS button that will trigger the siren alarm on the outdoor unit. 3.Night Vision: See who is outside your home even with the low light as the ZEB-VD4 Smart comes with night vision feature thats helps you see who is outside even in the dark. 4.Lock and Unlock.: The video door phone also comes with features like lock and unlock once connected your door you can open your door with just a click of a button on the VD4 Smart.