These are the Baxter House version of the Knock Down Dun. These are about the most realistic mayfly imitation available. These flies excel during any sustained mayfly hatch. The trout will choose this pattern over the naturals every time.
This is a species specific Mayfly pattern. Available in the following important mayfly species. Blue Quill, Hendrickson, March brown, Green Drake, Isonychia, Cahill, Sulfur, Blue Wing Olive