Item Type: Video Doorbell Material: Metal Battery Capacity: 1 x SY-1 Lithium battery 1200mAh (shipped with built in battery) Power Supply: Built in lithium battery, or USB charging cable power supply TF Card: Maximum support 32G (shipped without tf card) Ringtones: 4 Languages: 3 Night Vision lights: 2, 12U Suitable Door Hole Size: Approx. 14-60mm / 0.55-2.36in Adaptable Door Thickness: Approx. 35-110mm / 1.38-4.33in Indoor Unit Size: Approx. 95 x 85 x 17mm / 3.74 x 3.47 x 0.67in Outdoor Unit Diameter: Approx. 65mm / 2.56in Package List 1 x Indoor Main Engine 1 x Outdoor Machine 1 x USB Charging Cable 1 x Metal Hanging Plate 6 x Screw 1 x English Operation Guide 1Smart Visual Recognition: The doorbell uses smart visual recognition technology that can recognize faces and alert you when someone unfamiliar is at your door. 2Easy Installation: Wireless doorbell camera is easy to install, screw punch installation or adhesive backing on the door or wall, no wiring, convenient and fast. 3Advanced Functions: The doorbell also has advanced functions such as motion detection, night vision and bidirectional audio communication, allowing you to talk to visitors at the door even if you are not at home. 4Remote Access: You can use a smartphone or other device to remotely access the video from the camera and monitor your home even when you are not at home. 5Wide Range of Applications: Video intercom doorbell can be used in apartments, villas, hotels, offices, public buildings, and more.