The Compressor Para Kossie Dun was developed by Mick Hall, a renowned Australia fly tier. It was tied as a variant of the original Kossie Dun. This insect is one of the largest Mayfly species on the Australian mainland. It is also known as a Drake or a Green Drake. This particular pattern is representing the critical emerging stage of the Mayfly dun. In some cases it could be considered as a cripple dun. We have found this pattern works in most rivers on the eastern seaboard of Australia, whenever there are large pale Mayflies.