The chasen is carved from a single piece of bamboo into 80-100 fine prongs that create a smooth, frothy suspension when whisked rapidly in hot water. Each chasen is hand-carved by specialist craftsmen (primarily in Takayama, Nara Prefecture) and is considered a consumable tool — the prongs wear down after 50-100 uses. The number of prongs affects the froth: more prongs produce finer, creamier foam.