This necklace has a unique pendant which contains beeswax on the inside. A small amount of essential oils are absorbed into the beeswax and when the necklace is against your warm body, the oils are naturally diffused. Use it simply as perfume and/or for the beneficial properties of the essential oils! The beeswax is reusable and does not need to be replaced, even if using different oils. The chain and pendant are made of hypoallergenic stainless steel.