They have a device which progressively shines a light on a piece of paper while moving across the page and converts the brightness of the reflected light into an audio signal. Once it reaches the edge the paper is incremented and the process repeats. Each of these segments of sound are sent via a standard telephone connection to a similar device on the other end which uses the sounds to reproduce the image on the original paper on a new sheet of paper. This can be used to send forms, letters, black and white pictures, and even chain letters. It also forms the basic underpinning of a significant fraction of formal communications with landlords, employers, medical systems, government offices, and so on.