Feature: 1. 2‑wire system, only two wires are required to transmit power, audio, video and control signals. All signals are transmitted through 2‑wire non‑polarity central power supply. 2. Support in and out, branch and mixed mode, support two‑way hands‑free intercom between indoor units. 3. Integrated power supply, support up to 2 outdoor units and 6 indoor monitors (only 3pcs monitor includes), support group calls function. 4. 7in color TFT LCD screen, no radiation, low power consumption, 1024 x 600 high definition. 5. Outdoor unit built‑in white light LED night vision device, support night vision effect. 6. Indoor intercom function can be set to mute, volume, brightness and contrast are adjustable, can unlock 2 locks at the same time. 7. Durable aluminum alloy outdoor unit, effective against rain and oxidation, can well monitor the outside of the door. 8. Use plug‑in connectors and DIP switches for quick installation and support flexible cable connection. Specification: Item Type: Video Door Phone Material: Aluminum Alloy +ABS PlasticOutdoor Camera:Aluminum alloy external device with white LED night vision cameraCamera: 1/3in CMOS 1000TV LineViewing Angle: 92°Minimum Illumination: 0.5lxVideo Output: 1Vp-p /75ΩConnection Method: BUS 2-WireInstallation Method: Wall-MountedWorking Temperature: -30℃-50℃Camera Size: Approx. 240 x 169 x 24mm/9.4 x 6.7 x 0.9in Monitor Screen: 7in LCD Effective Pixels: 1024 x 600 Connection Method: BUS 2-Wire Monitor Size: Approx. 151 x 80 x 38mm/5.9 x 3.1 x 1.5in How to Use:1. The indoor unit, outdoor unit, and power supply are connected by cables, and the power cord is connected to power supply.2. Adjust the color and brightness of the display, and ensure the doorbell's intercom function can be used.3. Connect to the electronic lock at home, can realize doorbell unlock.. Package List: 2 x Outdoor Unit (Camera)3 x Indoor Unit (Monitor)1 x DC24V 2.5A Power Supply2 x 4 Core Connection Terminal Wire4 x 2 Core Connecting Terminal Line3 x 2 Hole Terminal1 x 3 Hole Terminal1 x 4 Hole Terminal3 x Bracket1 x Screw Pack1 x User Manual