Audio/video camera is an accessory to the Vtech IS7121-2 (sold separately) and requires this phone system/doorbell answering system to work. Like Caller ID for your front porch, this video doorbell allows you to screen visitors before answering the door, without worry of being seen. This weatherproof video camera automatically snaps a photo and sends it to the phone handsets (sold separately) when visitors ring the doorbell. You can then stream video, audio or both with just two buttons. With DECT 6.0 digital technology using the latest-available frequency band, this interference-free device provides superior voice and sound quality and higher protection against eavesdropping than 2.4GHz and 5.8GHz phone systems. Camera also features adjustable camera angle; automatic infrared night vision; backlit keypad and display; battery and AC power modes; and intercom to the cordless handset (sold separately). Battery life lasts one year.