This wireless doorbell set with plug-in chime B431E from Byron is a breeze to install and includes a handy additional chime that you can install at another location or take along as you move around the house or garden. All you need to do is mount the doorbell at your front door and plug the plug-in chime into a mains outlet in the house. The doorbell is illuminated and has a personalised nameplate. You can choose from 4 different melodies for the chimes' sound and control their volume. The doorbell works on a 12V 23A battery, which is included in the delivery. The portable chime requires 3 AA batteries, which are not included.