Silver polished stainless steel / 18k gold plated stainless steel Allergy information: Hypoallergenic Length: Adjustable 16 ½" / 42cm + extends to 19 ¾" / 50cm 10mm Laser engraved wave charm Silver polished stainless steel / 18k gold plated stainless steel Waterproof & Non-tarnish 1.2mm diameter thin and delicate chain Shipped within 1-2 business days 14 day returns Waterproof | Tarnish resistant | Hypoallergenic Made with full stainless steel/18k plated stainless stee, laser engraved ocean wave charm which is completely waterproof. Tarnish and worry-free. Enjoy the elegance of 18k gold plated 316 stainless steel with the strength of medical grade 316 stainless steel. With a stainless steel chain, there's no more green discoloration on skin. Stainless steel is a metal that is very stable and does not react. Classified hypoallergenic for sensitive skin. The advantage of stainless steel over other jewelry like sterling silver is that stainless steel is a metal that does not tarnish nor corrode by chemical reaction with water or other substances like perfume or creams. It is a metal that stays shiny and doesn't require maintenance, unlike sterling silver or other gold plated jewelry.