Possibly the best all purpose mayfly pattern! Works in a wide variety of dry fly scenarios when mayflies are present - and sometimes even when they aren't.
The matte demon stone is an effective stonefly nymph pattern. Works well early in the season for steelhead, and great for trout when stoneflies are present and you need a muted presentation.
This is a great, and very effective euro-nymph, but don't let that limit you - you can fish the tungsten jig napoleon just as effectively under an indicator, no euro-gear required!