JOVIVI Natural Lava Stone Gemstones Chakra Heart Pendant/Locket Necklace 28" DURABLE & STRONG CHAIN: High quality 28" adjustable length up to 29.5" with a lobster claw clasp FUNCTIONAL & COMPACT: No more need to carry your big bulky diffuser with you. Now you can simply WEAR your personal diffuser around your neck and take advantage of the benefits of essential oils all day long! SIMPLE & EASY TO USE: The pendant opens from the top like a locket and is specially designed to hold our lava stone. You simply add 1-3 drops of your favorite essential oil onto the lava stone and your ready to enjoy your personal diffuser. LAVA STONE (17mm) - This reusable, round black lava stone provides the best way to diffuse essential oils on the go. Not only does it give the necklace a great look, making the antique silver stand out, but it is a porous material that will hold the oil for hours. It holds the oil longer than the traditional leather discs or poms. Heart PENDANT - This necklace is a round Heart filigree designed locket-style pendant, approximately 0.7"(18mm) in diameter and is silver-plated copper.