Tibetan singing bowls (also known as rin gongs, Himalayan bowls or suzu gongs) are a type of bell, specifically classified as a standing bell. Rather than hanging inverted or attached to a handle, singing bowls sit with the bottom surface resting. The sides and rim of singing bowls vibrate to produce sound characterised by a fundamental frequency (first harmonic) and usually two audible harmonic overtones (second and third harmonic). Singing bowls were traditionally used in Asia and the tradition of making sound with bronze bowls could go back 3,000 or more years to the Bronze Age.