Wireless door chimes are versatile and installation free but the receivers can drain batteries incredibly fast this one has a mains powered receiver that plugs into any convenient 13 amp socket so it doesnt need batteries it also has a built in socket so you dont lose a useful plug point the wireless bell push comes supplied with fixings and a long life 3v cr2032 battery which will work for around 20 000 uses it transmits a radio signal to the indoor plug in receiver which can be posit