Crystal singing harp is a musical instrument made of pure quartz crystal, with C D E F G A B C 8pcs notes. We have large and small different sizes. All tuned at 440 HZ or 432 HZ frequency (CDEFGABC Note), the tubes are precisely tuned. Each tube is a note of the C major scale. (same as each chakra). We also have colorful models for sale, adding a visual and energetic element to the instrument.