Super Duo Beads are a glass Czech made, Two Hole Seed bead. Super Duos consist of a pressed glass bead with guaranteed size and dimension. They measure 2.5x5mm, with two .8mm holes . They are a coloured glass with many coating options: Transparent, Opaque, Matte, Color Lined, Picasso, Luster, AB Coating & Magic Line. This is a 24 gram tube.