The Stimulator is designed to imitate a stonefly, hopper, or caddis fly. It has proven itself to work in a variety of dry fly fishing situations and deserves to be in every trout fishing fly box. Hollow hair and ample hackle allows this fish fly to ride high and even hold a fairly heavy dropper fly. Whether tossing it during a stonefly hatch or using it as an attractor fly the stimulator is always worth several casts. Look for more stimulators here.