This is the "go to fly" of my guide service. There is a brass or tungsten bead hidden in the thoraxand under the wing case. As a rule of thumb use: 5/32 beads on size 10, 1/8 beads on 12 &14, and 3/32 on size 16. Fished upstream with an indicator....making sure to contact bottom once and a while....DEADLY.
