Looking for help identifying this gobo style foam wall

[melovine]

http://youtu.be/3BccdlVAnK8

At 1:02 you can see how the amps were separated with a rather thick foam wall. Any clue if these are custom or something similar that could accomplish this effect?

 

[AudioGeekZine]

I don't think it's custom, probably just mattress foam but I have no idea where to get it. I've been to one studio that had huge foam chunks for around a drum kit. Must have been 6' x 4' and 12" thick.