The Otto Tuning Forks are used for relaxation, and for sending vibrations into the bones. The forks are tuned to the frequencies of 32hz, 64hz and 128hz. They vibrate at a low pitch due to their weighted prongs. Start your explorations with the 128hz. These forks are especially effective when placed on the sternum, vertebra and meridian points.Used primarily for relaxation and grounding, the Otto Tuner kit resonates with the deeper tones of the Earth. The Otto Tuner is the note of C in the diatonic scale.These frequencies project sound into the physical body, especially in the bones. The effect is to replenish the tone of tissues and to align them well. Great for sore muscles and relaxation of bones.This Set consists of 3 tuning forks.These 3 tuning forks are based on 32 Hz, 64 Hz and 128 Hz. Benefits are- C-32Hz - works with skin and hair to stimulate nerves and hair. Good for grounding.C-64Hz - helps loosen sacral ligaments and stimulate and balance between the sympathetic and parasympathetic nervous systems. Useful in emotional trauma and grounding.C-128Hz - is used for grounding and relaxation. This frequency is also used by EMT's and Paramedics to locate fractures in bone. All our Tuning Forks are made from special grade Aluminium alloy and frequency is guaranteed to tuned to an accuracy of +/- 0.25% which is very good for healing.