I made mine. It is custom fit to the openings in the top of my tank. I use it all the time...not only for photography, but also any time that I'm working in there because it helps me see things more clearly.
Wow..the tank has really changed since this photo was taken!
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400 gal reef. Established April, 2007. 3 Sequence Dart, RM12-4 skimmer, 2 x OM4Ways, Yellow Tang, Maroon Clown (pair), Blonde Naso Tang, Vlamingi Tang, Foxface Rabbit, Unicorn Tang, 2 Pakistani Butterflies and a few coral gobies
My Tank:
http://www.canreef.com/vbulletin/showthread.php?t=28436