The Chimney screen is the veteran smokers version of heat management systems and is ideal for smaller bowls that do not fit the more modern Heat Management devices such as the Kaloud Lotus or AOT Provost.  This device is the most popular form of heat management in other parts of the world, especially Europe and is starting gain some notoriety here in the states.  The Unglazed Bowl is the perfect fit for this hookah and is not included with this product.