Nelson does plenty of flow research in his own shop on his own bench. He likes tailoring the port size and shape to each individual application. He uses a probe inside the port to determine where the air is moving fast and where it's moving slow. As he says: "The probe measures inches of water being pulled, and when I probe into a port, I'm looking for the highest water depression. This is normally a busy area that could use some help. The width of the short-side radius (in the corners), along with the port roof, is where I do most of my work."