FISH GILLS Holographic mylar side-cheeks to glue on to your flies to create a broader profile and help hold materials in shape, especially with longer flies. Easily fixed with epoxy glue. Used along with our holographic eyes, they provide extra detail and realism in your patterns, and a flashy aiming-point at the front end of the fly right where the hook is! Highly recommended, all my own life-like patterns wear their gills with pride!