This stretchy necklace is made of 14k gold filled beads, and is the perfect addition to any outfit. Whether you're dressing up for a special occasion or just want to add a touch of luxury to your everyday look, this necklace is sure to make a statement. Swim, sweat, and sleep in it without a worry in the world. Model is petite, wearing 15" which is intended to be a choker on most people. How thick is 3mm?