This convenient radio doorbell transmits the bell signal via radio. You can either connect the transmitter cheaply to a 230 V mains socket & save space, or use it as a mobile handheld device. In the latter case, the device is powered by built-in batteries, which are charged during stationary operation in the socket. The mains plug can be simply folded into the casing to stop it from getting in the way. You can power the radio transmitter either using a 12 V battery or by connecting it to an existing doorbell system. Our tip: Since along with the acoustic features the receiver also has a very well visible optical display, this bell system is ideal for loud work places & for persons with hearing impairment.