John Barr designed his Barr&';s Baetis Emerger in the 1970&';s, and they have become one of the best emerger patterns in use todayExcellent trout, bass or panfish flies. Must have fly fishing fly for early spring or fall mayfly hatches.Set of 3 Emerger Fly Fishing Flies Hook Size 16 Essential on rivers where insect nymphs and larvae are an important trout food.