Features:  With surveillance, intercom, unlock, hands-free, ringtones choice, ringback function Indoor unit:  1. 7 inch high-definition digital screen, no radiation, low power, high definition widescreen image.  2. hands-free intercom function.  3. electronic control lock function.  4. monitoring outdoor functions.  5. image brightness, color, ring volume, speaker volume can be adjusted.  6. 16 polyphonic sound optional, will not always hear the monotone of the doorbell.  7. interior wall design.  Outdoor unit:  Camera: 1/4'HD color CMOS can reeach 700 line.  Camera lens: 3.6mm.  Camera viewing angle: 92 degrees (adjustable).  Call duration time: 120 Seconds.  Monitor duration time: 60 Seconds.  Power consumption: Static state <0.5W, calling <10W.  Power input: AC 100V-240V 50/60 Hz.  Power output: DC15V.  Indoor monitor: 180*120*18mm.  Outdoor camera:138*98*40mm.     Note:  1 (Outdoor Unit) can work with 1-6 (Indoor Unit).  2 (Outdoor Unit) can work with 1-4 (Indoor Unit).     Package includes:  1 x Outdoor camera.  1 x Indoor monitor.  1 x AC adapter.  1 x 5m 4-core Connection cable.  1 x 2-core Connection cable