Icelandic sheep hair is a very long, soft and very mobile, naturally tapered hair. It's great for pike/musky and saltwater flies, and perfect for long tube patterns. This material maintains its translucence when wet and provides a lot of movement. Compared to other icelandic sheep wool, Sybai's is generally longer and has a higher proportion of long hair to underfur. In short (no pun intended), more of the qualities you're paying for.