Door bell uses advanced microcomputer manufacturing technology， and automatic human infrared sensor， high performance，energy and easy using. Specially designed to prevent false alarm device，it is triggered when someone walking infrared sensors，will send an alarm or music， greetings， etc.， high sensitivity. That close to your life， and can be widely used in offices， homes， shops，factories， etc.， is not only convenient， and gave you pleasure and a sense of security.Specification:Work voltage: 3 AAA batteries/DC9V powerFor your safety and quickly receive the item， batteries are not included.Quiescent current: 10MAWork current: 100MADetection range: 2~8MView Angle: 60\u00b0\uff08up and down\uff09 110\u00b0(left and right)Sound pressure: 75db-95db\u00b15dbSensing method: infrared sensorAmbient temperature/humidity: -25\u2103~55\u2103 5%~95%RHSize: 81MM*81MM*42MMColor\uff1awhiteMaterial: ABSFeature32 ring tones to choose from， 3 kinds of sound types， 4 kinds of volume.2-8 meters distance detection， wide angle， safety.2 kinds of power supply mode.Relatively large sensing range of product， you can use the stickers to adjust the window size.How to install:1. Fixed bracket on table or the position you want， with screws or double-sided tape.2. Install 3 aaa 1.5V batteries (Alkaline batteries are recommended)， or use the DC9V power adapter， and open the switch to \u201cON\u201d3. Select the type of sound you want or music， and adjust the volume appropriately.4. Install the doorbell on the stand by a bayonet， when a visitor enters， the induction doorbell will be issued to the voice you chose.5. As a warning role， install in the balcony， doors， windows， stairs and other place thieves easy access to. And adjust the angle and height of appropriate probe， when the thieves entered the zone， immediately audible alarm.6. music catalog:Like: Westminster chime， Fur Elise， knock， ding ding ding dong， OH Susan， iron at Nick numbers， Minuet (Bach )， Serenade (Haydn)，a military march， Minuet (Beethoven)， minuet， Lambada (carnival of life)， Moscow Nights， jasmine， lullabies， Huang birds，birthday song ， little star， London Bridge， ding ding dong，etc. NOTE1. Do not use this product in contact with corrosive materials or falling from a height.2. After each installation of this product to open the battery， switch beep， over 15 seconds into the normal working condition.3. If the product has automatic sound or not normal， check the battery or power supply or installation location is correct (to avoid directly at the light-emitting lamps / sunlight) If the ambient temperature is too high (above 30 degrees)， the detector\u2019s detection range will be narrowed phenomenon (this product， normal 2-5 meter sensing distance of the most stable， as far as up to 8 meters)，which is a normal situation! When the doorbell sounds weak， or barking phenomenon， replace the battery， try to avoid the doorbell mounted directly to the location of the air flow changes(such as: air-conditioning vents， exhaust fan port， electric furnace nearby，etc.)do not install place in the sun and rain， do not go near mobile phones and other wireless devices.4. A long time out of the machine， please switch to the \"OFF\" position and remove the internal battery.5. It is recommended to use the 7th AAA alkaline batteries， used batteries should be placed in designated collection barrel.For your safety and quickly receive the item， batteries are not included.For your ease of installation， shipping with 2 M5 screws and 1 double side tape\uff1a\uff09Package include1x Automatic Door Bell1x double side tape2x screws2x plastic strips