This item is a wireless doorbell set, which consist of a transmitter and a receiver. LED indicator light will flash, emitter work and the receiver receive the order and then send out the beautiful music reminded you the VIP visit, the blue-ray LED of the receiver will regular flash along with the music. This product is of waterproof function and can be put outside the door. Description Receiver: 10cm x 5.8cm x 2.8cm, Emitter: 8.1cm x 4.5cm x 2.3cm The work voltage of the receiver: DC 4.5V (3* AAA battery,not included) working current: 80mA Static current: 0.8mA(Ultra-low power ,can extend battery life); Power: 2W Music: 36 cord music for option Sound: 25-80dB (4 grade volumes) Remote Control / Distance: 100m (in ) Work Frequency: 315MHz; Work Voltage of the Emitter: 12V (Battery Model: 23A 12V) Work Electricity of the Emitter: 15mA(20 times a day by calculating, a high quality0) LED Indicator: press the send button, LED indicator light will flash, emitter work and the receiver receive the order and then send out the beautiful music reminded you the VIP visit, the blue-ray LED of the receiver will regular flash along with the music. This product is of waterproof function and can be put outside the door Temperature: -10 ~50 degree centigrade Package list: 1 * Wireless Digital Doorbell 1 *