Brill version made with a very thin core and transparent fibers mixed with ultraviolet ones. It is a very interesting material for tying nymphs and wet flies, giving a translucent and ultraviolet effect to the bodies. Also excellent in combination with cdc thoraxes and soft hackles that increase its effectiveness and imitativeness. Also available in the packaged version on a card. - 4 meter spool - 5 mm. fibers