A chamar is a yak-tail fan which is waved at the end of arati. This represents the offering of the element of air back to its source, cool the deity, keep insects away. Waving the chamar is also a gesture of honoring the Deity and Her royal power. Considered ritually pure, the only hair that can be used in puja is that from the tail of a yak.  It is extremely difficult, even in India, to find a chamar made of real yak-tail hair.  We still have some left.  Approx. 25″ long.