#ad For wearing two necklaces at once: ten en route jewelry necklaces, six shorter chains and pendants listed at 37 to 42 cm and four longer pendants and Y-chains listed at 45 to 87 cm, each sold on its own, plus two of our pendant explainers and Jewelers of America's necklace length guide. At jeweldipity.com we compare jewelry by stated material, size and care; for each piece we noted the chain length and extension the brand lists, the plating and base metal, and whether the brand lists it as waterproof or says to keep it away from water. Full shortlist on jeweldipity.com