Extra-secure fold-over (clamshell) brass bead tips. Approximately 3mm cup. Designed to completely hide your knot. Tips have an extension with a hole on both sides. Silver plate nicely matches the color of sterling silver. Your jump ring or split ring goes through the holes and helps keep the bead tip shut. Once you fold and press the halves together, it looks like a round bead! Hint: Tie a 2mm seed bead inside, instead of just knotting the cord.