Fly tying beads have evolved! The heads of most natural stonefly species typically have the same distinctive, flat profile that is almost triangular in shape. The large head is broad at the back where it meets the thorax and has with a long flat nose that tapers to the front. Stoneflies typically have prominent eyes situated at the rear of the head. 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.