A prayer wheel contains mantras on a spindle. Spinning the wheel clockwise will have much the same effect as orally reciting the prayers. Prayer wheel range from hand held ones spun by pilgrims, to huge ones at temples. The most common manta is Om Mani Padme Hum, the mantra of the Bodhisattva of compassion Avalokiteshvara, spoken by most pilgrims as they spin their prayer wheels.