These were designed for use with KOrda's flying back leads. The hole inside the bead is tapered so if it is fished with the larger hole facing towards the rod then it will pass more easily over a leader knot.
The small hole will then rest against the top of the anti-tangle system stopping the large bore of the back leads from sliding down the anti-tangle system which would stop the flying back lead 'flying' back on the cast.
Purely coincidentally, they are perfect for use on the Dark Matter leaders should you wish to fish them chod style and anchor the hook link on one of the two tungsten collars designed to hold the leader down on the lakebed.