Fly tying beads have evolved! Natural mayfly nymphs that swim and burrow into the bottom are very similar and generally have an oval-shaped, slightly elongated head that is gracefully curved at the front, but is flat at the back where it attaches to the thorax of the insect. They typically have large, prominent (egg-shaped) eyes. This is a profile that is impossible to replicate with standard beads or cone heads but easy to incorporate into your fly with this product. 15 heads per package. See Other Details for recommended hook sizes.