Prayer wheels are an important part of Tibetan Buddhism.
When turning the prayer wheel of the request should be cherished, that is located in and on the drum mantras work for the benefit of all beings, eliminate their suffering and bring them happiness.
Related can be visualized that the mantras radiate while rotating light and dissolve unfavorable karma.
A still higher idea is to concentrate during the rotation that the prayer wheel, which make them rotating person, and the act of turning even a unit with the creation.
The prayer wheels are made of brass and copper.