A popular and widely used fly. Originally designed and tied by John Barr. It most closely resembles a stonefly, although they are not common in Iceland. However, many anglers have faith in the fly and believe it works well where Arctic tadpole shrimp are found. It has the characteristic of being quite heavy, as its body is made of copper wire. Therefore, it sinks well to the fish and works well with another fly in the so-called “dropper setup”.