Set of 2 wireless doorbells with battery-free doorbell button is designed for homes, apartments, offices, hospitals, shops, etc. It does not require any cable connection. It provides sound and visual signals. The receiver (doorbell) is plugged directly into a ~230V socket and the transmitter is powered by the electromechanical transducer, thus no battery is required. The learning system is used to easily log in additional buttons. The range in the open area is 200m. Receivers have a 4-step volume adjustment and 36 polyphonic ringtones to choose from.