In one embodiment, a housing is disclosed. Said compact structure adjoins the wall of the shed on the outside and is set up with the possibility of being removed longitudinally on guide means for positioning the movable assembly in a position opposite any one of the openings providing access to the shed. A user-adjustable stopper is mounted upon the dispensing head and is configured to interact with the steps to selectively limit depression of the trigger to thereby align a selected one or more of said metering compartments with the port. The system includes a user or customer interface device operatively connected to an associated signal distribution circuit for both receiving telecommunication signals from the associated signal distribution circuit and transmitting telecommunication signals to the associated signal distribution circuit.