voodooalpaca's video: A selection of Buddhist prayer wheels from Bhutan

A prayer wheel is a cylindrical wheel traditionally with the mantra Om Mani Padme Hum written in Sanskrit on the outside. 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. Many thousands (or in the case of larger prayer wheels, millions) of mantras are then wrapped around this life tree. According to the Tibetan Buddhist tradition based on the lineage texts regarding prayer wheels, spinning such a wheel will have much the same meritorious effect as orally reciting the prayers, allowing the practitioner to accumulate wisdom and merit. Water wheels - turned by flowing water. The water that is touched by the wheel is said to become blessed and carries its purifying power into all life forms in the oceans and lakes that it feeds into. Wind Wheels - turned by wind. The wind that touches the prayer wheel helps alleviate the negative karma of those it touches.