I made this necklace using tarnish resistant 16k gold plated flat link chain. It has a 16k gold plated clasp and 18k gold plated connecting rings. There are extenders making it adjustable anywhere from 19"-23" in length. I added a wavy gold heart pendant with an 18k gold plated connecting ring. * Purchase will arrive in pretty packaging * Chain Size Details: the size of jewelry making chains is about 10mm long, 3.5mm wide and 1mm thick. * Pendant Size Details. about 17-20 x 16-18 x 2-4 mm, hole: 3 mm