Features: 1. Ultra-thin design of the touch button indoor machine, which is stylish and luxurious. 2. The indoor machine can be connected with up to four channels of CCTV camera (there is no CCTV camera in this package), and four pictures are displayed on the indoor machine at the same time. 3. After turning on the monitoring, it is in the monitoring state. When there is a doorbell rings, the doorbell function is preferred. 4. Features function of hands free intercom, electronic unlocking and outdoor monitoring, etc. 5. The image brightness, chroma and volume can be adjusted at will. 6. Waterproof outdoor machine, and it also has infrared night vision function. 7. Ultra-thin indoor machine design, tempered plexiglass panel with touch key, it has white backlight and keypad tone, which is nice-looking and luxurious. 8. Up to 16 chords ringtones can be selected, it can give you sweet-sounding and pleasant using experience. 9. Outdoor call: press the didong button to talk to people inside. 10. Indoor call: press the monitor button to see the outside, and then press the intercom button to talk to people outside. Specification: Condition: 100% Brand New Switching Power Supply: AC 110v-240v 50Hz DC 15V2A Machine Current: Less Than 800mA Call Delay Time: 120s±10% Monitoring Delay Time: 60s±10% Camera Sensor: for SHARP 1/4 420 Line, Night Vision, Ircamera Lens: 3.6mm 92 Degrees Function: Monitor: Press the Monitor Key of the Indoor Machine, and You Can See the Situation Outside Machine. Unlock: the Indoor Machine Has the Function of Unlock (note That This Doorbell Does Not Have Lock) Speakerphone: Speakerphone Function Optional Power Plug: AU, EU, US, UK Voltage: 110-240V Package List: 1 x Outdoor Machine 3 x Indoor Machine 3 x 5m 6-Core Wire 3 x Power Supply 3 Pack of Screw Accessory 1 x Instruction 1 x 2-core Terminal Wire (which can be used for locking) 3 x Video Adapters (can be connected to CCTV camera) 6 x 6-core Port Line Note: After receiving the doorbell, please use five meters 6-core wire to test whether the doorbell works normally.