18-20" adjustable snake chain Calypso necklaces. 3.3mm diameter. Plated over brass. Silver plate is a thin surface layer of actual silver. Perfect for Calypso beads and other beads with a hole size 4.4mm or larger. Finished with swivel clasp and 2" steel adjuster chain. If you have a bead that almost fits, try removing the end jump ring before stringing bead, then re-attach jump ring.