The size of this bead is 4mm. It's flat on one side and a single groove down the center on the other. Yummy and unusual to come by. Made in Czechoslovakia. They are from the early 1900's. What a find! Glass nailhead beads were used in the days of the flapper to embellish garments before sequins were developed. Also sold in lots of $3/24, item #8979. You will receive 48 beads per lot here.