This mini macrame hanging car diffuser is made with recycled 15mL essential oil bottles. So with each purchase you are saving the earth, go you! Artificial car fresheners can contain hundreds of chemically based, harmful synthetically made fragrances that are dangerous to any human who consumes the scent. Ditch the chemicals and choose essential oils as your car freshener of choice. The bottle is filled halfway with liquid absorbing lava stones. How does the diffuser work? Simply add 3-5 drops of your favorite essential oil or even make your favorite custom blend. The absorbent lava stones will soak in the essential oil of choice and act as a natural, chemical free car diffuser. The more drops of oil added, the stronger smelling your diffuser bottle becomes. Ready for a new scent? Simply place your lava stones in a cup of hot water for 5 minutes and then soak off water with towel. The stones are now ready for a new scent. Each bottle comes with the lid in order to get the most life out of each diffuser use.