Find SuperDuo beads for sale at Barrel of Beads. Matubo SuperDuo Seed Beads are a Czech made, glass two hole bead. They are a pressed glass bead with guaranteed size and dimensional stability. They measure 2.5x5 mm, with two 0.8mm holes. There are many coating options: Transparent, Opaque, Matte, Color Lined, Picasso, Luster, AB Coating, Magic Line & Halo Beads.