An ash catcher is used in smoking equipment with Water Pipes or bongs. Its purpose is to catch the ash and other debris from the burned material, preventing it from entering the water or reaching the smoker's mouth.

Ash catchers typically consist of a small glass chamber that attaches to the joint of the smoking device and contains a removable bowl or downstem. When the user takes a hit, the smoke travels through the bowl or downstem and into the water, while any ash or debris is caught in the chamber. This helps to keep the water clean and the smoke smoother and more enjoyable to inhale.

Ash catchers come in various shapes, sizes, and designs and can be made from different materials such as glass, silicone, or metal. They are often used by smokers who want to keep their smoking devices clean and extend their lifespan, as well as those who prefer a smoother smoking experience.