An extender chain is a small piece of jewelry that can increase the length of a necklace or bracelet. It is attached at one end and has a clasp at the other, allowing you to adjust the size of the jewelry to fit comfortably. Full definition
Gold plating, spring ring clasp Length: 17.5» with a 2.5» extender chain for adjustable length Resin, rhinestones, clear acrylic stone beads (shamelesslysparkly.com)