This all-in-one motion sensor doorbell combines infrared detection and alarm functions and is popular for its convenience and practicality. A detection range of 2 to 6 meters, a horizontal detection angle of 110 and a vertical detection angle of 15 allow you to install this pirate doorbell in many places, e.g. such as shops, sheds, offices, apartments, garages, warehouses, restaurants, public buildings, etc. Designed with 3 mode switches, volume buttons, music buttons, power button and power connector, This welcome alarm doorbell is easy to use and works with a flashing light when someone walks by to activate it. You can use it as a front doorbell to say "Hello, welcome" or as a motion sensor alarm, with a continuous alarm sound like "Woo..." for about 15 seconds, or as a store/home pirate chime play selected music.< /p> Technical parameters: Working current: &lt;80mA. Working temperature: -10-50< /p> Detection range: 4-8m Detection angle: 110. Installation height: 1.5m-2.5m Size: 80*50*75mm (length*width*height) Wireless working frequency: 433MHz Sound: up to 90 decibels Battery installation diagram: pull Remove the battery cover from the switch to open the battery cover. The installation is correct, press the battery switch and the installation is complete. Package Includes: 1xM5 Motion Sensor with Alarm and Doorbell