Super Duo Beads are a Czech made, glass Two Hole Seed bead. Similar in shape to the Twin bead, but with a few very important differences. Super Duos are a pressed glass bead with guaranteed size and dimensional stability, this makes them perfect for beadwork and countless patterns. They measure 2.5x5mm, with two 0.8mm holes . They are not simply coated crystal but actual colored glass with many coating options. We sell these tubes in mix tubes of matching colors.