This accessory will help cool your vapor in two different ways: the first cooling element is the installed glass beads, which will absorb a lot of the heat from your vapor. Essentially, the heat will remain in the beads and simply not be inhaled. The second cooling element is that the natural airflow forces your vapor to pass through all these beads, so it doesn't just hit your lungs straight away.
Whenever you have a complex airflow level, you'll notice a significant increase in cooling. As a bonus, the beads also act as a filter, so if any particular matter gets into the stem, the beads will catch those bits before you have a chance to inhale it.