The best open doorbell antenna for receiving 200 meters from the remote control (open area);Built-in 16 polyphonic ringtones, suitable for different scenes and different styles, highlighting the taste;Built-in digital buttons, easy to adjust the size of the music sound; under its monitoring, it can effectively monitor the human movement in a variety of environments, the detection range: 120 degrees, 5M human movement. Product description tSpecification: Material: Plastic Dimensions: about 6.5 x 9 x 3 cm/2.56 x 3.54 x 1.18 inches, 6 x 9 x 4.5 cm/2.36 x 3.54 x 1.77 inches Follow the steps using 1. Place the correct battery in the detector and receiver unit. 2. Make sure the battery is in the correct position. 3. Turn the switch inside the detector to ON until the battery is installed. 4. Install the detector correctly on the front door, window frame, driveway, boardwalk, backyard or wherever you need it. 5. Then turn on the receiver and set the volume to Hi or Lo. 6. Now the remote sensing system uses infrared sensing technology. 7. Place the receiver in an easily accessible place. 7. When the detector detects movement, the receiver will emit a sound and the LED light will flash. 8. Please wait for 30 seconds to activate after turning on the detective & receiver. 9. Please install the two devices 3 feet away from the ground for best performance. Useful tips Do not place the detector where the wind will blow it. And try to keep the detectives Package includes: 1Piece wireless doorbell