Extra-secure fold-over/clamshell sterling silver bead tips. Approximately 3mm cup. This tip has an extension with a hole on both sides. Designed to completely hide your knot. Once you fold and press the halves together, it looks like a round bead! Your jump ring or split ring goes through them and helps keep the bead tip shut. Hint: Tie a 2mm bead inside instead of just knotting the cord.