The Uni-Com Plug-through Door Chimesimply plugs into any 13A socket around your home, and with the plug-through feature, your mains socket is still available for use with other appliances.The door chime is wireless, so no wiring is required, and with an extensive operating range of up to 150m, you never have to miss a visitor or delivery. The bell push is water resistant (IP44 rated) .It has 3 operating modes - chime sound only, blue LED alert light only and both together, you can set your Door Chime to operate exactly as you want it to. With 30 different chime melodies to choose from, 90dB (A) sound output with volume control and a flashing colour change chime alert, you will always know when somebody is at your door.Bell push powered by 1 x CR2032 Button Cell Battery (supplied) .Compatible with all other Wireless Uni-Com door chimes.