Marco's Comments:
Booklet by Gregorio with 9 special cartons depicting sheep, used for a routine where the magician/mentalist rapidly counts the number of sheep printed on the cards. The mathematical principle behind is from Bob Hummer and the routine is interesting for an audience of magicians or lovers of this kind of effects. It is not really a trick suitable for professional performances.
However, the cards and the booklet are of very good quality and the trick is a pleasant pastime.