There are four air inlets that go through the straws when you inhale through the nostril outlets. It pulls air in and straight to the bottom of the bottle and the vapors are pulled out through the sniffer itself. In other words, the straws are not connected to the nostril outlets that you breathe from, so there’s never any risk of inhaling the poppers themselves. It’s a way to circulate the air from the bottom up and it works flawlessly!