The Evolution Stonefly tungsten beadhead is molded after the common stonefly head profile— broad with prominent eyes at the back where it meets the thorax, and a long, flat nose that tapers to the front. Evolution beadheads are simpler to use and have greater versatility than ordinary beads. The holes are slightly bigger to fit a much larger range of hook styles and sizes. This extra space is designed for lead or lead-free wire to be used with the beadhead to create better body profiles. It also allows you to create neater flies by hiding excess materials, eliminating the ugly “thread collar” so typical of many beadhead nymph patterns. Take your tying and fishing to the next level by adding the final, previously impossible, element of realism to your stonefly nymphs.