This fly was given to me 25 years ago by a fisherman on Manzanita Lake, in Lassen Park, CA during a callibaetis hatch. He was catching fish and noticed that I was not. He said he had been developing this fly for quite sometime. The low profile and the black wing make it hard to see on the water. The black wing is essential. I actually had a swallow come down and pick my fly up off the water! Its the only callibaetis dry fly I use.