One size fits most. Elastic strap goes from the sides to the bottom of the balls. Accented with Platinum Plated Nickel Free Cross Chain. Gemstone Beads are Natural Sinkiang Turquoise, Round about 12mm in diameter. The dangle pendant is a Lead Free and Cadmium Free Tibetan Silver Snake, about 26mm long, 11mm wide, 1.5mm thick. The natural stones add great color and a little weight to this sexy two piece set.