Doorbell ringer mains socket type?

[masona]

A electrician told me but forgotten the name of it that you can get a wireless doorbell which the bell ringer is on the adapter type,then plug into any ring main socket anywhere up to the range of 100 metres (?).The idea is,so I can use it in the summerhouse plugged in the socket and hear the doorbell.I can't see it anywhere on the net as I really don't the name of it,does anyone know of it or heard of it?

Don't want the type where you carry like a bell ringer pager type on your belt etc.

TIA.

 

[breezer]

this what you want?

 

[masona]

Thanks,spot on even better,found one with two bell ringer

You could even have one in your Dalek ,but don't go further than 100metres away