1、PROFESSIONAL MONITORING LENS: The professional grade lens on this doorbell includes a high definition CMOS image sensor, with automatic exposure, white balance control, and a high light sensitivity angle providing clear image for your property, making sure that you can keep a close eye on everything happening in and around your home. 2、VISUAL INTERCOM FUNCTION: The visual intercom function of this doorbell allows you to screen visitors before answering, giving you peace of mind and helping to prevent theft and burglary. Perfect for office, hotel, apartment, factory, and more. 3、BUILT IN POWER ADAPTER: The built in power adapter is designed to save space and reduce waste, with an environmentally friendly, low energy consumption design. This means that you can enjoy this doorbell without having to worry about the impact it is having on the environment. 4、ONE BUTTON LOCK CONTROL: The one button lock control feature of this doorbell makes it easy and convenient for you to control electric locks, electromagnetic locks, and electric plug locks. 5、INDOOR GROUP CALLING: With the indoor group calling function of this doorbell, you can enjoy convenient and easy communication with anyone inside the house. With just one button press, you can call everyone together, making it easier to have important conversations. 1 x Outdoor Unit1 x Indoor Unit1 x Iron Sheet3 x Connection Cable8 x Expansion Screw8 x Metal Screw1 x Manual1 x Changer Item Type: Video intercom doorbellMaterial: ABSWeight: Approx. 993g / 35.03ozOutdoor unit camera: 1/4 HD CMOSOutdoor unit light: 6 infrared lightOutdoor unit resolution: 800x600 pixelsIndoor unit voltage: AC 100-240VIndoor unit resolution: 800x480 pixelsIndoor unit wiring method: 4 lines