Crystal Graphite Rainbow OBEAD-00030/98537 Czech O Beads - Let your imagination soar with these unique donut shaped beads. These high-quality, durable Czech pressed glass beads feature a large 1.5mm hole that gives them endless possible uses in your beading designs. Czech O beads come in a large array of colors and finishes. They measure 1x4mm and come in a tube of approximately 285 beads.