This pattern is basically a combination of a midge emerger and a small mayfly. Tied like an RS2 nymph, with a stubby wing and a split fibbit tail, it can work as an emerging mayfly. The profile and size also allow it to pass it self off as a midge emerger. When the water is low and clear, this midge/mayfly really shines. We use this patter almost any day we are fishing on the San Juan River, especially from mid-day into the early evening. Available in size 20 & 22.