This necklace comes on a 32” rhodium plated chain. The black cylinder piece is a lava rock so you can add your favorite essential oil to it and be fashionable and smell awesome at the same time! I recommend a q-tip with 1-2 drops of your fav oil. Wipe the q-tip on the lava rock and give it maybe 20-30 seconds to absorb the scent and then wipe off any excess oil. This will avoid issues with staining clothing. Make sure it is dry to the touch. It will still carry the scent for 1-3 days then you can repeat or try a new scent.