This is a complete necklace with a Sterling Silver lobster clasp. Due to the flexibility of this rubber necklace, we recommend only the lightest charms and pendants, to avoid tugging. End diameter is 3.2mm, so any pendant or charm must have a hole 3.5mm or larger to fit onto necklace. All sterling parts are stamped .925. Quantity: 1 complete necklaces. 2mm wide, 16 inch (41cm) total length including clasp. Sterling Silver lobster clasp is 8.4mm.