Night Vision: Equipped with 6 IR LED light sources, with high definition night vision, built in high sound quality microphone, effectively monitor the outside. Wide Application: Suitable for use in villas, homes, office, government units, etc., installation of the door machine, and wall hanging of indoor machine . Screen and Camera: 7 inch high definition large screen, 1/4in HD CMOS camera, clear images, two way radio, smooth intercom, and equipped with unlocking function. Practical: 16 ringtones to choose from, four levels of volume adjustment, supports 60 seconds of calling, 30 seconds of monitoring, suitable for AC100‑240V power supply. Installation: Four core wire system, 30 meters need 0.5 mm wire, 50 meters need 0.75 mm wire, 100 meters need 1 mm wire, easy and convenient installation.