The Bowl holds a layer of Incense Sand plus the Incense itself.  The Sand stops the Incence from sticking and also helps to maintain the temperature around the Incense.
Please note when ordering replacement Bowls remember to include the two dimentions A & B as shower in the photo to ensure your replacement Bowl fits.
Note - ( All our ovens are hand made and are not an exact size - this is why we need the dimentions. )