The Bead Head Olive Sparkle Pupa Fly is designed to match an emerging Caddis as they appear underwater. The antron case imitates the gas bubble Caddis have to help propel them to the surface. When Caddis are hatching fish will move out of their way to inhale this fly. The Sparkle Pupa patterns can be fished as a dropper, on the swing or as a nymph in deep water. The many different colors and sizes allow you to match any emerging Caddis on your local waters.