Self-Powered Wireless Kinetic Door Bell with Plug in Chime Self-powered: No batteries are required for both transmitter (push button) and receiver. With a press of the transmitter, it generates electric power itself and sends a stable signal to the receiver. Modern and Practical Design: Comes with a stylish appearance and practical functions. Lightweight and sensitive. Easy to install: Just plug the receiver into a power socket and attach the transmitter to the door, you don't even have to make holes. 38 Ringtones & 4-Level Volume: 38 different CD-quality sound tunes, 4 levels of adjustable volume from 25dB to 85dB, memory function for sound and chime selection Waterproof Doorbell: IP44 Rated transmitter with waterproof ring seal, works between -10°C to 50°C, withstanding tough weather conditions. Enjoy the freedom to install it anywhere inside, on your door frame outside or in your garden.