Features: 1.Multifunction: Motion sensor detector has welcom, anti theft, door bell, alert, color light and night light function, high sensitivity, stable and reliable. 2.Adjustable Design: 4 levels volume and 4 levels brightness can be adjustment, with 36 melodies, meet for the different environment, convenient and ptactical. 3.Long Distance: Sensor angle is horizontal direction 100 degrees, vertical direction 15 degrees, sensor distance is approx. 2?8M, related to ambient temperature. 4.Loud Alarm: Wireless infrared doorbell provides 113dB alarm, effective in deterring thieves, provides high security to your property and loved ones. 5.Wide Application: Suitable for shops, luxury hotels, offices, factories, homes, villas, driveways, walking paths, supermarkets, restaurants etc. specification:Item Type: Wireless Infrared Doorbell Material: ABS Transmitting Receiving Frequency: 433.92MHz Working Environment Temperature: Receiver: -10 to +60 Infrared Detector: 10 to +33 Working Environment Humidity: