The Hookah Heba Diffuser attaches to the bottom of the Hookah Down Stem and is used to break the water into smaller bubbles for increased water filtration, air flow, and an overall calmer Hookah smoking session. The Heba Diffuser Set includes two Diffusers, one small and one large. The small Diffuser is recommended for smaller Hookahs and Hookahs that have a narrow style base. The large Diffuser is recommended for larger Hookahs and Hookahs that have a wider style base. Please note: This product will fit larger stems, such as those on most Khalil Mamoons, with slight modifications.