1. Multifunction: The motion sensor detector has functions of welcome, anti-theft, doorbell, warning, colored light, and night light, high sensitivity, stable and reliable. 2. Adjustable Design: 4 volume levels and 4 brightness levels can be adjusted, with 36 melodies, suitable for different environments, convenient and practical. 3. Long Distance: The sensor angle is horizontal direction 100 degrees, vertical direction 15 degrees, the sensing distance is approx. 2-8M, related to the ambient temperature. 4. Loud Alarm: Wireless infrared doorbell provides a 113dB alarm, effectively deterring thieves, providing high security for your property and loved ones. 5. Wide Application: Suitable for shops, luxury hotels, offices, factories, homes, villas, driveways, walkways, supermarkets, restaurants, etc. Item Type: Wireless Infrared Doorbell Material: ABS Transmission Reception Frequency: 433.92MHz Working Environment Temperature: Receiver: -10℃ to +60℃ Infrared Detector: 10℃ to +33℃ Working Environment Humidity: <80% Storage Temperature: -20℃ to +70℃ Receiver Battery: 3 AA batteries (not included) Infrared Curtain Battery: 3 AAA batteries (not included) 2 x Receivers 1 x Infrared Curtain 1 x Sticker 1 x Screw Kit 2 x Base 1 x Universal Adjustable Bracket 1 x User Manual