... , intercom & chimes 2.user-friendly design 4-in-1 security door viewerbuilt-in digital camera, color display, intercom & chimesUser-friendly designso ... citizens and kids can operate!Hassle free installationreplace the optical door viewer in minutesHigh sensitive camerathe visitor’s picture can be ... with run time of more than 1 year anti-thief door guard,personal flat ...