Davej wrote:
Just got a Pelican box for my non-waterproof camera and I was wondering
if anyone understood the nature of the "automatic pressure equalization
valve?" I looked on the Pelican website and could not find anything
explaining how it worked. Anyone know?

I found it. They have a FAQ that says the valve is a gore-tex membrane
that blocks water but is permeable to gas. Now I just wish they made a
box that was smaller but deep, like 6"x 6"x 6".