Video door phone 1, one door station can support up to four indoor phones, if needed, it can be extended to two door stations supporting up to four indoor phones. 2, dual talking, surveillance, intercom and remote door unlocking. 3, led in the door entry system provide a clear picture even in night time. 4, double ding-dong ring or chord melody ring 5, 30 second ring tones are available, 30 second surveillance, 120 second intercom. One set per gift box, the other details can be discussed
