Ozz
First your going to think I'm following you.
I like the price, from Blue Seas they are around $40 Cdn, I guess I have to breakdown and get an address just across the border.
I liked the document on venting battery boxes. Lots of good information at that site.
http://www.bdbatteries.com/hydrogenventing.php
I looked up H2 gas at Wikipedia and a 4% concentration becomes explosive and that is right under where I'm sleeping, I guess that is why the Goodyear Blimp is filled with Helium.
martin