1x Split Wireless Doorbell Smart Multifunctional Doorbell Detector : 200 meters away (open space) to pick up the doorbell antenna, it was best to open; Built - in 16 polyphonic ringtones suitable for a variety of different styles, highlighting the taste; Built - in digital buttons, easy to adjust the music sound size; There are three operating modes: 1 music ringtone; 2 blue flashes; 3 ring flash Can be effectively monitored from various environments within the scope of human movement monitoring, detection range: 120 degrees, 5M of human body movement Infrared probe installed in the door, home wireless doorbell, someone from the door enters, the doorbell will be issued with a sound reminder It can be used for hotels, boarding houses, boarding houses, shops, warehouses, houses Specification: Material: plastic Size:. 6.5 x 3 cm / 2.56 x 3.54 x 1.18 in, x 4.5 cm / 2.36 x 3.54 x 1.77 in Follow the instructions for use 1, Put the appropriate batteries in the detector and in the receivers. 2, Make sure the batteries have been placed in the right places. 3, Switch the button to ON which is inside the detector until the batteries are installed. 4, Properly mount the detector on your front door, frame , driveway, walking path, yard or anywhere you need. 5, Then turn on the receiver and adjust the volume to lo. 6, The remote sensing system works with infrared sensing technology. 7, Place the receiver in an easily accessible place. 8, the detector will detect a sound, the receiver will hear a sound, and the LED will flash . 9, Please wait 30 seconds after turning on the detective and the receiver to activate. 10, units should be installed 3 above ground level for optimal performance . Useful Hints Do not place the detector where the wind will move it. Also, try to keep the detective on the right path to the receiver for optimal performance . includes : 1 wireless doorbell