Description:Infrared InductionWhen switching to alarm mode, no matter day or night, it can sense thieves within 4-8 meters through infrared rays, and emit a loud alarm sound. Horizontal detection angle 110 degrees, vertical detection angle 15 degrees.Multi ModesIn addition to the alarm mode, the doorbell also has sound/music mode, sound mode features ding dong, hello welcome in human voice, with flashing blue light. Music mode will play the music of your choice with flashing blue light.Easy OperateWith mode button, volume control, music volume control, there are 32 ringtones to choose from, and the volume can be adjusted in four levels, easy to use.2 Power Supply MethodPowered by 3x AAA battery(not includes) or 9-12V DC power adapter, you can choose the power supply method according to the actual situation, can be used for a long time.Various PlacesSimple and modern appearance, durable and sturdy, can be used in your home, hotel, offices, shops, warehouses, shopping malls, office buildings, apartments, etc.Specification:Material: PlasticColor: WhiteSize(LxWxH): About 83x45x85mm/3.27x1.77x3.35inchPowered by: 3x AAA battery(not includes) or 9-12V DC Power AdapterInstallation height: About 1.5-2m/59.06-78.74inchVolume Loudness: 85dB5dBPackage includes:1pc x Wireless Doorbell1pc x Screw PackNote:1. Due to the light and screen difference, the item& 039;s color may be slightly different from the pictures.2. Please allow 1-2 cm differences due to manual measurement.