Install a practical and easy to use doorbell system in your home without any wiring simply plug the chime unit into an indoor socket fix the bell push to the outside door or wall and you are ready to go you dont even have to lose a socket as the unit has an integral socket built into it theres a choice of 256 channels to avoid any chance of interference with your neighbours bells and 8 pleasant tunes to select you can adjust the volume of the ringer up to 75db using the rotary dial