The first prayer wheels, which are driven by wind, have been used in Tibet and China since the fourth century. The concept of the prayer wheel is a physical manifestation of the phrase "turning the wheel of Dharma," which describes the way, in which the Buddha taught. A prayer wheel is a cylindrical wheel (Tibetan: འཁོར་ལོ།, Wylie: khor lo) on a spindle made from metal, wood, stone, leather or coarse cotton. At the core of the cylinder is a "life tree" often made of wood or metal with certain mantras written on or wrapped around it.
They are made to be turned by hand, wind, water or firepower. When part of a temple, people will circle the building clockwise and turn the wheels as they walk. Thus, they gain the benefit of circumambulation of the sacred building as well as the prayers sent up by the prayer wheel.