Product supplied with a transmitter, two receivers that plug into an outlet, double-sided to paste your doorbell and two screws with their ankles if you want to attach to an area that does not correspond to the double face (Arfff! Also a leaflet but I have not used it, I've been feeling in!). The receivers consume really nothing more anyway! The transmitter just needs one of those small batteries (A A23, like most wireless doorbells!). More than enough scope!