Singing bowls are 'traditionally' made of an alloy consisting of various metals, often seven, each associated with a heavenly body. May also be played by rotating a mallet around the outside rim to produce a sustained musical note.
Singing bowls are a type of bell that vibrates and produces a rich, deep tone when played. Also known as singing bowls or Himalayan bowls, Tibetan singing bowls are said to offer powerful healing properties. 
Many proponents claim that the vibrations of a singing bowl can produce beneficial changes in the body by reducing stress, "harmonizing" the cells, and "balancing the body's energy system." Some also claim that Tibetan singing bowls can stimulate the immune system and produce beneficial changes in brain waves.