"Because they have a tungsten bead, they plummet quickly, with even small versions getting down fast.
I typically fish them beneath an indicator, either as the bottom fly below a larger pattern, or in tandem with a second scud of a different size and color, or, two to three feet under a Chubby Chernobyl in a dry/dropper rig.
Because of the tungsten beads, they even work well for Euro-nymphing. However you like to nymph, give these a try...I am finding they work well even in streams that have no scuds!"
- Signature Tyer Mike Mercer