Mercer's Jiggy Pale Morning Dun Nymph is a heavy Euro fly with a yellow wing case to imitate the nymphal stage of a PMD. Because of the Tungsten head and jig hook, this is a pattern works best in deep water or fast currents. Works great fly on the Missouri's technical tailwater trout. Use this in a double nymph rig or as a dropper. Release the fish harmlessly - barbless hook.