Wireless Door Chime, Security Sensor, Call Bell, Notification Bell, Ping Pong, Security Prevention Wireless Motion Sensor Chime Features: 1. Principle: The transmitter will detect and notify you with the sound of the receiver. The reception distance of the receiver is 150 meters outdoors without obstacles, 40-50 meters with obstacles, and 90 meters compatible with high visibility indoor A great item to bring to your home, shop, office, warehouse, and other places to prevent crime . High-sensitivity Infrared Sensor & Multi-functional: It can accurately detect people, and the detection distance is 9.8 - 5.6 ft (3 - m), the detection angle is 15° up and down, and 100° left and right. Receiver volume is adjustable, 38 kinds of music optional, 3 volume control and LED indicator. You can set it with or without sounds (there is sound: sound + display light, silent: display light only) 3. Caution: Please avoid installing in places with high airflow or near heat sources. (e.g. cold air outlet, ehaust fan, electric furnace or nearby heating) Do not epose the sensor to direct sunlight, rain, or near the metal 4. Easy to Use: Wireless so there is no need compatible with troublesome wiring work, and it is very convenient to install. The simple design lets you notify you of visitors and incoming calls with a single touch, so you can use it with confidence Material: Plastic Receiver Working Voltage: 110V - 40V Sensor Working Voltage: 4.5V Working Range: up to 0m Infrared Sensing Distance: 3m - m Power compatible with Sensor: 3 Batteries(Not Included) Receiver Size: .6cm 8cm 3.3cm/.99&quot 3.15&quot