A pre-cooler works by locking in place where your removable bowl usually sits in a bong and adding an extra layer of water for the smoke to filter through bringing extra smoothness and a frosty chill to your smoke.

This Pre-cooler sits vertically between the bowl and stem of the bong, it works by splitting the smoke through 4 pathways whilst bubbling through the internal chamber. This allows the smoke to chill more and increase the size of your hits.