Product Details: Model: A10 Working Range: 300 meters Music Selection: 60 music tracks (default Ding Dong Ding Dong) Volume Selection: 5 levels Power Supply Voltage: The receiver supports AC100-240V voltage. AC Doorbell: The transmitter uses a 12V 23A battery, and the receiver plugs directly into the power supply. Play Mode: Music Selection Setting: Press the music selection button Loop Mode: Long press the song selection button for 3 seconds And hear two "beeps" to enter the loop state. At this point, each time you press the transmitter, the doorbell song changes. Appearance: Transmitter: 75*51*20mm Receiver: 95*65*24mm Scope of application: homes, commercial and residential areas, office buildings, hospitals, restaurants, factories and other places. Installation Notes: 1. Tear off one side of the double-sided tape and stick it to the bottom of the transmitter. 2. Tear off the other side of the double-sided tape and stick it on the wall outside the door. PS: After the double-sided