What is a portable filtration device commonly used for smoking various substances?

A portable filtration device commonly used for smoking various substances is a bong. Bongs are designed to filter and cool the smoke before it is inhaled, which can enhance the smoking experience by making it smoother and less harsh on the throat and lungs. The water in the bong filters out some of the particulate matter and can also help to cool the smoke, which can make it more enjoyable for the user.

In contrast, while a pipe can also be used for smoking, it does not typically have a filtration system like a bong, making it less effective at reducing harshness. A whistle has no connection to smoking as it is a musical instrument. Similarly, a cup is unrelated to smoking; rather, it is typically used for drinking.