Stem (bong)

A stem (a.k.a. female piece) (no. 4 at the picture) is a component of bong, sits in the base and pokes out of the chamber at a degree higher than the water level. It holds the conepiece/bowl and enables smoke to pass through the water when in use. The stem collects resin over time which can clog the stem, and reduce the air flow through the water.