These are the trout beads from the folks at....... Trout Beads. The hole in these accomodates Eumer X-Small tubing or HMH Micro Tubing which can then be nested inside other tubings or used alone. For example, you would just add the bead to the X-Small Eumer and then nest inside Medium to tie the fly. You can turn any fly into an egg sucker or simply add some junction tubing off the back to make basic egg patterns.
These are the ones that Greg Senyo is featuring on many of his current tube fly patterns.
The 6mm come 40 to a pack and the 8mm come 30 to a pack.
Hot colors listed here...especially the caramel roe! Colors are top left to bottom right.