Downstem
From Wiki Weed
Most commonly found on bong, bubbler, and oil rig, the downstem is the part of the piece which reaches from the bowl and delivers the smoke down into the water. They normally have a glass joint at the top which is either 14 millimeters or 18mm wide that accepts attachments such as a weed bowl, oil skillet, nail, etc.
File:Downstem - Weed Depot.jpeg
marijuana smoking tool
