Prayer wheels, called Chokhor in Tibetan, are very common religious objects in Tibet. A hand held prayer wheel is a hollow wooden or metal cylinder attached to a handle. Om Mani Padme Hung mantras are printed or etched in relief on the cylinder. Attached to the cylinder is a lead weight with a chain, which facilitates the rotation. Tibetans use prayer wheels to spread spiritual blessings to all sentient beings and invoke good karma in their next life. They believe that every rotation of a prayer wheel equals one utterance of the mantra, thus the religious practice will in return help them accumulate merits, replace negative effects with positive ones, and hence bring them good karma. The religious exercise is part of Tibetan life. People turn the wheel day and night while walking or resting, whenever their right hands are free while murmuring the same mantra. Buddhists turn the wheel clockwise. Bon followers turn the wheel counter clockwise.
Prayer wheels vary in size and type. Not all prayer wheels are hand held. It is common for bucket-sized prayer wheels to be lined up on wooden racks along walking paths circling monasteries and other sacred sites, for the benefit of visiting pilgrims. Larger water, fire, and wind prayer wheels are built so that they are empowered by the flowing water, the flaming light, and the blowing wind which drive them, and can later pass their positive karma to all who touch them.