Standard beads for tying bead head nymphs and streamers.....also referred to as Cyclops eyes or Cyclops beads. Sold here in Nickel/Silver but also available in Copper, Black and Gold.
Sizes:
3/16" for hook sizes 4-8,
5/32" for 8-12
1/8" for 10-14
7/64" for 12-16
3/32" for 14-18
5/64 for 16-20
1/16" for 18-22
24 per package.