mEssentials Tree of Life Essential Oil Diffuser Necklace Locket (316 Stainless Steel Hypo-allergenic) Stainless Steel 316L Surgical Grade Stainless Steel Essential Oil Diffuser Necklace. This necklace is Hypoallergenic, Surgical Grade, and Waterproof. We guarantee the Highest Quality! Your necklace will never rust, corrode, irritate your skin, or stain! This amazing necklace is designed to last a lifetime. This locket is 25 mm (approximate 1.0 inch) in diameter Chain is also 100% Stainless Steel 2.5mm wide x 24 inches long. LIFETIME GUARANTEED SATISFACTION - Two strong magnets closure and solid back insure you never have to worry about getting oil on your clothes Buy with confidence! Every essential oil diffuser necklace is covered by our NO Questions asked