1mm x 1mm iridescent snow white crystal glass bead, comparable to size 20/0 seed bead. These tiny tubes have tiny holes as well, so use size 15 beading needles and O or OO beading thread. One hank contains twelve 20 inch strands.Czech maco tubes are tiny tube beads briefly produced during the 1990's then discontinued. We like to describe them as liquid silver. They are the creme de la creme of bugle beads used by some top designers for fine embroidery work.