Buddhist prayer wheel made from a human skull, Tibetan, 18th-19th century.

Tibetan 'Mani', or prayer wheels, are devices for spreading spiritual blesings and well being. Copies of the mantra (prayer) 'Om Mani Padme Hum', printed in an ancient Indian or Tibetan script, are wound onto an axle in a protective container, and spun around. Larger decorative versions of the mantra are often carved on the outside cover of the wheel. Tibetan Buddhists believe that saying this mantra, or spinning its written from, invokes the blesings of Chenrezig, the embodiment of compasion. Small hand-held wheels, like the one shown here, are the most common.