Solfeggio tuning forks are a set of precisely calibrated instruments designed to produce specific frequencies known as the Solfeggio scale. These frequencies are believed to have originated from ancient musical traditions, potentially including Gregorian chants. The Solfeggio scale is thought to resonate with the human body's energy field, promoting healing and balance through vibration. 

The scale initially had six core frequencies and was later expanded to include three additional tones.

Tuning forks are believed to work through resonance and entrainment, potentially helping the body return to its natural frequency.

Solfeggio tuning forks can be used in various ways, including near the ears, above chakras, or on acupressure points. They may also be used to enhance meditation, amplify crystal energy, or incorporated into energy healing.