Marble's Extra-Lum Expert shotgun beads have 500 percent more light gathering qualities than standard florescent beads. The UV protected fiber optic cable is highly polished to further guarantee as much light transfer to the eye as possible. The extra bright bead really stands out. Bead size is .090" (nominal).
Material: Blued steel body
Gunsmithing Required: Yes
6x48 OverSize thread with major diameter of .146"
500 percent more light gathering qualities
UV protected fiber optic cable.