The Magic Ring was a standard instrument of the magicians during the middle ages and renaissance. It is described and illustrated in the most infamous of all grimoires, the Goetia. King Solomon used his own magic ring to seal into a brass vessel the demons he had previously employed to build the temple, so the ring is of great importance in solomonic magic. For some odd reason, the ring of the Exorcist is not illustrated on the plates which accompany the published Mathers-Crowley edition of the Goetia. I have here reproduced it from the manuscript version of the work. It was very faulty in the manuscript, requiring me to reconstruct the letters of the names MICHAEL, ANEPHENETON and TETRAGRAMMATON that appear on the ring. If you construct this ring, it would be better to write these names in Hebrew characters. The ring is to be made either of silver or gold. I would guess that the names MICHAEL and ANEPHENETON are to be written on the outside surface, and the name TETRAGRAMMATON on the inside surface.