The measurement of these beads is 5.5mm round. These are a flat faceted transparent disc shape. These are from the early 1900's and were produced in Bohemia. Glass nailhead beads were used in the days of the flapper to embellish garments before sequins were developed. Great find! The image does not do these justice. The variety of reds within each strand is amazing. You will receive 24 rare nailhead beads per lot.