Bong

A bong (also known as a water pipe) is a filtration device generally used for smoking cannabis, tobacco, or other herbal substances. In the bong shown in the photo, the smoke flows from the lower port on the left to the upper port on the right. In construction and function, a bong is similar to a hookah, except smaller and especially more portable. A bong may be constructed from any air- and water-tight vessel by adding a bowl and stem apparatus (or slide) which guides air downward to below water level whence it bubbles upward ("bubbler") during use.