The Portable And Plug In Door Chime Set features two chime units so that you can cover your whole house and garden. One chime unit is portable to carry or place where you need, and the other plugs in to any 13A socket.This door chime set has an impressive range of up to 100 meters from the battery-powered and water-resistant bell push, which is easy to attach with the secure adhesive pad. There are 26 different chimes for you to choose from, with volume control.