18-Inch Gold-Tone Curb Chain Adjustable Choker Necklace / Jewelry with 3-Layer Engraved Crescents Pendants (Size: 18-19) Material: highest quality metal . A curb chain is a variation of cable chain with uniformly sized round or oval links but these are twisted and often diamond cut so that they lie flat along a surface. It comes with a lobster clasp for easy and secure wear. Necklace has a 1-inch extension chain to accomodate more neck sizes. PLEASE SEE MEASUREMENTS IN THE PICTURES.