Black Diamond Avalung II 2009: Let’s get serious -- this is the tool that could save your life. The Black Diamond AvaLung II is one of the most important developments in avalanche safety since the avalanche beacon. It allows the user to be able to breathe during an avalanche. The AvaLung is a simple filtration device which draws air directly from the snow pack. Even dense avalanche debris consists of approximately 50% air. The AvaLung membrane increases the surface area from which you breathe, making it possible to pull this air from the snow. You breathe in and out through the tube. The patented system within the AvaLung separates the O2 from the exhaled CO2, which is directed away from the air intake and out the back of the vest to diffuse through the snow pack. The Black Diamond AvaLung is designed for backcountry powder skiing, snowboarding, alpinism, and snowmobiling.