This is a Tesla valve. It's basically a no moving parts one way valve that Nikola Tesla invented and it's a 3D printed valve and so you can see the silhouette of the valve structure in here. This is the impeded direction and this is the unimpeded direction and you'll see that if I blow through the unimpeded way I get airflow and if I blow through the impeded way the airflow is resisted by the fluid itself traveling through the geometry which is just amazing that that can happen so Nikola Tesla is a smart guy.