Satkowski's Flashlight Hex is a killer Hexagenia Limbata adult mayfly imitator. The glow in the dark fibers can be "charged" up with a flashlight for the evening hatch. Often the very best time to fish the Hex is a dark and beyond. While the fly is big. Why not have a big and glow in the dark fly!!
The Flashlight Hex is a great pattern to fish when you have big trout eating Hex flies all around you and you need a highly visible pattern.