These sound bars are suspended in sturdy wire above a base of quality wood. The sound bars are made of a special aluminum alloy that produces rich, clear and long-lasting tones. These are used in healing, because of the special sounds in pure frequencies. The sound vibrations that these "energy chimes" produce are rich in natural overtones, which contain the healing and harmonizing effect, creating clarity, concentration and deep relaxation. Energy chimes are used for healing and relaxation. The incredible resonance helps in focusing attention during meditation. Also perfect for Feng Shui energy work and when balancing the chakras. These chakra sound bars are tuned to the frequencies of the Higher Octaves, as indicated in the list below. These are derived from the 7 basic frequencies of the chakras. Crown chakra frequency 172.06 frequency of the higher octave - 2752.96 Forehead chakra frequency 221.23 frequency of the higher octave - 3539.68 Throat chakra frequency 141.27 frequency of the higher octave - 2260.32 Heart chakra frequency 136.1 frequency of the higher octave - 2177.6 Solar plexus chakra frequency 126.22 frequency of the higher octave - 2019.52 Sacral chakra frequency 210.42 frequency of the higher octave - 3366.72 Basic chakra frequency 194.18 frequency of the higher octave - 3106.88.