Air Intake from Window, Light?

Hi guys i really need some help.

Ive seen this video on youtube and the guy has some material which is placed over the window. This then allows air to come in and out but prevents light escaping and being seen from outside.

In the video the guy even says what the material is called but i just cant make out what he says at all...maybe someone here already knows or can make out what this guys saying.

Heres the video:
http://www.youtube.com/watch?v=gc8HCAadOfc

its at 2:58 were he says the name.

Thanks

Sorry to disapoint you but that is simply a blind, with a hardwood case specially created to go over the window "its the hardwood that defeats the light" and the exhaust circulation is created with the whole he creates and specialised fans etc.

He says loudspeaker cloth. Looks like the material that would go over a speaker in your house. But like what kn0tty said, the box is whats blocking most the light. The speaker material would make it harder to see whats behind the blinds, but light would get through it, you can see through it at 4:35 in the vid.

You can get some blackout curtains, or something like panda film which is light proof. Then cut a hole and attach a ventilation duct, and have the duct do a 90 degrees bend to stop the light, or spray some black paint inside it.

I think he says "speaker cloth".

thanks guys. i like the 90 degree bend method greentheory, i may have to use that.