The Powerbreather Adventurer is about snorkeling for hours on the reef without CO2 fatigue, safely. The Powerbreather has revolutionized swimming / snorkeling with the symmetric snorkel that brings in fresh from both the top tubes, and exhales your CO2 from the bottom. There is NO mixed CO2 air as with a traditional snorkel or face mask snorkels. Unlike a full face mask, with a Powerbreather you can easily dive deep, equalize your nose, and breathe safely with 100% fresh air, no gurgling, and no purging. Top valves on the tube only open briefly for an inhale, otherwise staying closed and keeping water out. You can literally hold your breath, dive deep, come up and inhale, with no water entering the snorkel. You can swim in choppy, wave like conditions without ever turning your head to breathe.