Connected doorbell and videophone - Universal - Electronic music. A wireless doorbell.(Gold) Highlights Universal Electronic music. A wireless doorbell.(Gold) Electronic music one for a wireless doorbell Feature: 1. 300 meters long, adjustable tone can change music, prevent string noise is not wrong, simple installation. 2. Indicator, receiver, volume key, select key, launch button. 3. Barrier-free distance of 300 meters penetration, strong penetration performance, linear air-ground distance reception The distance can reach 300 meters, note: the actual received signal changes from the visual environment, different signals due to different flash of the obstaclesare, the bell lights Specifications: Model: A20 Working Range: 300m Music Selection: 36 Ringtones Volume Selection: Adjustable volume size of 4 tone. Power supply voltage: transmitter uses 12v23a battery, receiver: 110/220V Size: transmitter: 7.7*4.6*2cm, receiver: 9*5.6*2cm Application scope: Company residential areas family, office buildings, restaurants, factories and other places.