This diffuser has many different names, in short, they are small pots made of clay. Their shape is also diverse, such as pyramid-shaped, round, tower-row, and so on. Usually this kind of clay jar diffuser has an opening that is used to add essential oil, and then a cork is used to close the opening. The essential oil penetrates through the clay jar and then diffuses into the air. The aromatic concentration depends on the amount of essential oil to be adjusted.
Advantages: Usually very cheap, and do not need electricity
Disadvantage: Aromatic after adding essential oil for a period of time thicker, and then slowly become light. So there is no way to control the concentration of essential oils in the air.