A great choice for medium sized flies or larger flies with less bulk, Uni 3/0 is a 220 denier polyester multi-filament thread recommended for flies #12 and up. Most of what we sell locally finds its way onto freshwater streamers and smaller saltwater flies. If you're using this thread for larger flies keep in mind that it is much more compact than Flat Waxed (i.e. less bulk and smaller heads) but not as strong.