Shelf mounted electronic display modules which preferably include a first outwardly extending portion containing an electronic display and an antenna positioned outwardly from a shelf rail when mounted and a second rearwardly extending portion containing a printed wiring board and a battery power source positioned behind and protected by the shelf rail when mounted. The first outwardly extending portion and the second rearwardly extending portion are preferably connected below the shelf rail by a bight portion which mechanically and electronically connects the first outwardly extending portion and the second rearwardly extending portion together to form a substantially U-shaped configuration.