A downstem is a crucial component in water pipes and bongs, serving as the conduit that directs smoke from the bowl into the water chamber for filtration and cooling. It’s typically a slender glass or metal tube that fits into the joint of the bong and holds the bowl at its top end.

Key Features:

• Function: Channels smoke from the bowl into the water for smoother inhalation
• Material: Usually made from borosilicate glass, but also available in silicone, metal, or acrylic
• Diffusion: Some downstems include slits or holes at the bottom (called diffused downstems) to break smoke into smaller bubbles for better filtration
• Length: Must be matched to the bong’s size—too short won’t reach the water, too long may not fit
• Joint Size: Common sizes include 14mm and 18mm; must match the bong’s joint and bowl size
• Removable vs. Fixed: Removable downstems are easier to clean and replace; fixed ones are built into the bong