Waterproof Door Calling Bell Wireless 433mhz Intelligent Door Bell 300m Range Smart Home Wireless Doorbell Home Appliance Home<br> Feature<br> 1. 300 meters long distance, adjustable tone can change music, prevent string noise is not wrong, simple installation.<br> 2. Indicator, receiver, volume key, selection key, launcher button.<br> 3. Distance barrier-free 300 meters penetration, strong penetration performance, receiving distance to the Air-to-Ground linear distance can reach 300 meters, note: the actual received signal visual environment changes, different signals due to obstacles are different<br> 4. Easy to install: press the button, ring the bell in the room, the receiver installed in the room can be plugged in, receiver intelligent flash, the bell lights<br> Specifications:<br> Model: A20<br> Scope of work: 300M<br> Music choice: 36 ringtones<br> Volume selection: 4 tone volume adjustable size.<br> Power supply voltage: transmitter uses a 12V23A battery, receiver: 110/220v<br> Size: transmitter: 7.7*4.6*2cm, receiver: 9*5.6*2cm<br> Scope of application: family business residential areas, office buildings, , restaurants, factories and other places.<br> Package Included:<br> 1X receiver<br> 1X emitter<br> 1X double-sided adhesive