1) Use a 4 core cable to connect the camera and monitor. The maximum distance is up to 100 metres. Different spacing, use cables with different diameters. 2) 4.3 inch colour screens. 25 ringtones to choose from. Can be switched freely. High quantity. Very suitable for 2 apartments / families. 3) 700TVL IR night vision, you can see outside day and night. Keep your home safer. 4) One key to unlock. This video intercom can be connected to an electric lock. You can open the door with the release button on the monitor. Very comfortable 5) Two-way hands-free and indoor monitoring. When a visitor rings, the monitor is activated and shows the image outwards. Press the answer button, then you can talk to the outside, press the answer button again to turn it off. Product specification: outdoor camera Material: ABS plastic. Camera resolution: 700TVL Night vision: up to 2 metres. Working temperature: -35°C ~ +55°C. Viewing angle: 85 to 92°. Performance: power from the interior unit Wire system: 4-wire system. Dimensions: 122 x 218 x 45 mm. Indoor monitor Screen: 4.3 inch colour TFT LCD. Effective pixels: 800 x 480 Wiring: 4 wire pin end of the room at the intercom: support Adapter input: AC100 - 240 V 50-60 Hz. Adapter output: DC 15 V 1500 mA. Housing: ABS plastic. Working temperature: -35 °C ~ 55 °C. Installation: wall mounting. Function: intercom, monitor, door unlock. Dimensions: 185 x 195 x 30 mm. Package includes: 1 x Outdoor Camera 2 x Internal Monitor 2 x Hanging Plates 2 x EU Power Supply 2 x 5 Core Connection Cable 2 x 4 Core Connection Cable 1 x 2 Core Connection Cable 2 x Pocket Screws 1 x Manual