Features: 3 apartment doorbell, each button corresponds to an indoor unit and does not interfere with each other. 7 inch color digital LCD screen, no radiation, low power consumption, really high definition 16:9 widescreen display. Ultra-thin design indoor unit, acrylic panel, blue backlight button, high-grade and beautiful to present luxurious style. Hands-free intercom function, active outdoor monitoring function, one-button unlock function. 16 music ringtones are available, pleasant to your ears, eliminating the annoyance of constantly hearing monotonous ringtone. The image brightness, chrominance and volume of the indoor unit are simultaneously adjustable. Outdoor unit supports electronically controlled unlock function, power-on unlock and power-off unlock require a special access control power supply. All metal waterproof, explosionproof, with 6 infrared lights for IR night view function. Indoor unit and outdoor unit can achieve intercom calling function. Specification: Condition: Brand New Material: ABS + PMMA panel Color: shown as picture Optional plug type: AU Plug, UK Plug, EU Plug, US Plug Display resolution: 840*480 Power supply mode: switch power supply AC110-240V 50Hz / DC15V 2A Whole unit current: < 800mA Call delay time: 120S ± 10% Monitoring delay time: 60S±10% Camera sensor: HD color CMOS; 700 TV lines Outdoor unit infrared night view function: IR on when less than 10LUX Indoor unit size: approx.225*128*23mm/8.9*5*0.9in Outdoor unit size: approx.180*90*20mm/7.1*3.5*0.8in Indoor unit installation method: wall-mounted Outdoor unit installation method: wall-mounted Package List: 3 * Indoor Unit (7 inch color LCD screen display) 1 * Outdoor Unit (Camera) 3 * Connection Cable (Standard 5m) 3 * Power Supply 7 * Cable Connector 3 * Screw Bag 1 * User Manual