Czech-nymphing before it was trendy here was called high-sticking or tight-line nymphing. Imitating a caddis larva, helpless in the current, the Tungsten Czech Caddis is a classic pattern of the genre.
The point is to make a dead-drift with the nymph (or nymphs). Use a floating line and no indicator. Make a short cast with less than 10 feet of line out of the rod tip. Follow the nymph with the rod and raise it high as the fly sweeps close, then lower the rod as it goes by.
Tie this pattern on a No. 10 egg hook or scud hook. Slide the tungsten bead up to the eye then tie in a length of dark wire and a clear plastic shell back. For more weight, wrap 10 turns of lead behind the bead. Build the body with a blend of yellow and natural hare’s mask dubbing. For the thorax, wrap two turns of orange dubbing, then several turns of dark brown or black dubbing for the head. Pull the shell back down and rib with the wire to finish.
— Gary Lewis, For The Bulletin