Tied to mimic a dun that has just emerged from its shuck and will remain on the water until its wings dry. It features a little extra flash in the body that makes it highly appealing to trout. This dun is also effective when fishing spring creeks. Per 2. Sizes: 14, 16. Colors: Callibaetis, Sulphur. Cancer and Reproductive Harm- www.P65Warnings.ca.gov. Type: Flies.