This tuning fork is designed to project sound directly into the physical body. Hit the top with the two weighted discs on it, and then place the stem directly onto the body. You can feel the sound go into you — a sonic massage tool. Use it to project sound into specific acupuncture points, acupressure points and other points and places associated with body therapies. Great for sore muscles, etc. Not for use on the head. Its frequency is 64 Hz.