The first information available about the dowsing pendulum dates back over 2000 years before Christ, Egypt. It was in the sarcophagi in Valley of the Kings  that were found objects used as pendulums, and dowsing wands made of different materials and adorned with precious or semiprecious stones. There is no specific standard as to the realization of a pendulum, there are different types from the classic pyramid shaped, with more particular spherical, brass, crystal, silver, wood, gold, with or without portatestimone. The only important thing is that the pendulum has a prospecting right to the table and the weight is not less than 12 grams. The length of chain or rope that is suspended is not subject to any rule, but we know that a chain is too long tends to slow down the oscillations, while an excessively short accelerations. We can say that for a pendulum weighing 12 grams, the ideal length should not exceed 20 centimeters