Trout and Trout anglers alike love a good "hot spot" so we incorporated this into our new split back mayfly nymph called RIO's Bubble Up May. This is tied on a barbless jig hook to keep it riding in the correct alignment whether fished as as dropper or alone. The v rib body provides a little bit of weight and keeps the fly slender. The picked out dubbing serves as legs struggling in the water. The poly tail reflects light giving the indication of life. We love this fly trailed behind small attractor dries.