Kingavon plug in wireless door chime is an easy to install plug in digital door chime that has a wireless range of up to 100m. It comes with 16 different melodies to choose from and can be plugged into any mains socket around your home. As this has a plug through socket, it enables you to use the socket that the chime/receiver is plugged into, without having to unplug the doorbell. The bell push requires a 1 x 12V A23 battery, which is included.