The invention is a radio transmitter that includes an antenna having at least one driven element and at least one reflector element. This allows one to see the contents in the dark and, in addition, constituting a light in the dark for the area surrounding the device, with the particularity that the volume of this device does not increase with respect to the devices meant to individually evaporate active substances and emit a light. The removal of at least one fluid from the well is controlled by the flow of gas into the injection conduit.