Platinum PT950 round snake chain necklace. Chain length: selectable (16" 18" 20" 22" 24" or 30"). Clasp type: Lobster. Weight: 16" 6.90; 18" 7.50g; 20" 8.20g; 22" 8.90g; 24" 9.60g; 30" 11.40g. Chain thickness: 1.2mm.