This pattern is already a proven staple, but putting it on a barbless jig hook with a tungsten bead allows Euro nymphing anglers to now enjoy it's fish catching benefits. Deadly on a tight line, it can still be fished under an indicator or trailed behind a foam dry.
The following are the bead sizes per hook:
Size 12 - 3.3 mm
Size 14 - 2.8 mm
Size 16 - 2.3 mm