The Sacred Solfeggio Tuning Forks are a set of forks in the sacred frequencies known as the Secret Solfeggio. Deciphered by Dr. Joseph Puleo using the ancient Pythagorean method of reducing the verse numbers to their single digit integers, the codes revealed a series 6 of electro-magnetic sound frequencies that correspond to the 6 missing tones of the ancient Solfeggio scale. These original sound frequencies were used in Ancient Gregorian Chants. The chants and their special tones were believed to impart tremendous spiritual blessings when sung in harmony during religious masses. These frequencies can now be produced with the Sacred Solfeggio Tuning Forks. Included forks and frequencies: 396 Hz, 417 Hz, 528 Hz, 639 Hz, 741 Hz, 852 Hz, 174 Hz, 285 Hz, & 963 Hz. Each kit includes a velvet pouch and mallet activator. About our Tuning Forks Our tuning forks are made from a special Aluminum Alloy that is heat treated giving them a very pure tone. The single fundamental frequency will remain constant for up to 15-20 years and the non-tarnishing material will not rust or corrode. Each fork is tuned by hand to an accuracy of +/- 0.25% or better. Please do not confuse our tuning forks with inferior products being made in China and Pakistan.