The Olive Perdigon Nymph Barbless Size 16 is a highly effective, slim, fast-sinking imitation for small olive and other upwinged nymphs. The smooth body reduces water resistance, allowing a compact fly to reach trout and grayling without excessive bulk.
Use it on a Euro nymph or tight-line rig through runs, riffles and glides. Match its olive shade to the naturals present and control the leader so the fly dead-drifts close to the feeding depth. One positive take is often enough to make this a trusted box favourite.