Each Crystal Singing Bowl in the Lotus series is matched in color and sound to one of the seven energy centers of traditional chakra teachings. This makes them particularly suitable for meditation as well as sound massage and therapeutic purposes, as the harmonic voice of the singing bowls can help relieve stress and bring body and mind into harmony. The indigo coloured 9" model is aligned with the third eye chakra and tuned to the A note. In the 432 Hz version, however, the concert pitch A is not at the standard Western frequency of 440 Hz, but at 432 Hz. This tuning is said to have, among other things, a particularly relaxing and calming effect. However, this singing bowl does not harmonize with conventionally tuned instruments. It should be played either individually or together with other 432 Hz instruments - such as Sela Unity Handpans.