Get up in a trout's gums with a Gummers
A Jig hook, CDC, UV hot-spot and the right tungsten bead to fish at the depth you want all add up to one thing, general-crunchablilty. These flies are absolutely lethal on rivers, we took them out for a test run and seriously thought about banning them on our local river, there not really fair on the trout... but trout aren't usually fair to us so we decided to sell them instead.
The tungsten beads range from a big 4mm bomb on the size 10 to a water tension slicing 2.5mm bead on the size 16, as you go down the size range you can pick and choose the right weight to get to the right depth you want to fish; either indicator style or short-line nymphing.
Hot pink beads pump UV and are great for big tailwaters or dirty water, and the black bead is stealthy enough for any big fussy brown in clearwater.