These Coq de Leon UV Perdigon Fire Tail Feathers are perfect for tying these extremely effective flies. Perdigon style flies consist of a bead head, usually tungsten, a tapered body built from thread or tinsel and a tail that is typically Coq de Leon fibers. Perdigon is Spanish for pellet. These flies resemble a sleek pellet that gets down in heavy water and works well even in highly pressured streams. These Fire Tail feathers are perfect for these style of flies.