The Grundig Wireless Doorbell with 2 Receivers on AC Power consists of a doorbell button and 2 receivers. Place the doorbell button at the front door and plug the receivers into the socket. The distance between the doorbell button and receiver must be no more than 80 meters. Thanks to the 2 receivers, you can hear the doorbell ring in 2 different places in the house. Choose 1 of the 6 melodies, or set a light signal for when someone rings the doorbell. This is useful for senior citizens and the hearing impaired. You can also determine the volume of the speakers in the receiver, so you'll always be sure to hear the bell.