This Byron DBY-23522uk Wireless Doorbell comes with a plug-in chime unit which can be plugged in to any standard UK plug socket, giving you the flexibility to plug your door chime in anywhere throughout your home. The chime unit will ring up to 175 metres (open distance) from the bell push.Easy to install, with no wiring required.Choice of 8 high quality melodies, multi coloured visual alert, adjustable volume & compatible with all other Byron "DBY" products.Wire free.Weatherproof.8 melodies.Volume control.Operating distance 175m.Fixings included.1 x CR2032 (included).EAN: 8711658442181.