1、APP Control: You can fully control the wireless doorbell alarm system through your smartphone to ensure home security and receive fast alerts in your house or apartment. 2、Multifunctionality: The alarm supports infrared motion detectors, 38 doorbell music options, 4 levels of doorbell volume, a detection distance of 12 meters, and WiFi connectivity. Note that it is only compatible with 2.4GHz WiFi networks and does not support 5GHz WiFi networks. 3、Customizable: You can add additional door and window sensors, motion detectors, wireless doorbells, and SOS remotes to different rooms in your home security system. It supports expansion with up to 9 sensors and 10 remotes or keypads, which can be added to the WiFi alarm station. 4、Easy Installation: No tools required. You can easily set up the wireless doorbell in under a minute without damaging the wall. The alarm host should always be connected to a DC power outlet. 5、Compatibility: Your home alarm system can be easily controlled via your mobile device for modes such as away, disarm, and home arm. It is compatible for iOS, for HarmonyOS, and for Android operating systems. Item Type: Wireless Doorbell Material: ABS Weight: Approx. 300.00g/10.58oz Doorbell Volume: 4 levels adjustable (including mute mode) Operating Current: <120mA Operating Temperature: -10 to 55 ℃ infrared human movement detector Infrared Sensor Battery: 3 AAA batteries (shipped without batteries) Solar Doorbell Battery: Polymer lithium battery 110mAh (included) Door Magnetic Sensor Battery: 2 CR2023 button battery 320mAh (included) Detection Distance: <12m Detection Angle: <120 degree Wireless Frequency: 433Mhz Transmission Distance: <150 meters (open area, no interference) 1 x Alarm 1 x Sensor 1 x Sensor Fixed Base 1 x Universal Bracket 4 x Screws 4 x Expansion Tubes 1 x Solar Doorbell 2 x Adhesive 1 x Fixed Plate 1 Pair x Door Magnetic Sensors