The singing-ring is a new instrument that invented in Japan.
It’s name “ring” is from the traditional instrument in Japan called “おりん＝ORIN”, from the Buddhism culture.
It produces drone sound with very rich over tones, it transforms your brain wave into alpha and theta wave easily.
Satomi plays singing-ring.
More about instruments of Omsenkyo.
Zanmai-kin
Grand sarod
Sanshin
Photo by taharo