Markers (like overhead markers, not really erasable and the tips can suck- try them out before your test (like when you get them) to see how they are), 2 laminated sheets, and noise-cancelling (?) headphones. That's basically it. You won't be able to really bring anything else into the room either (some centers allow earplugs & jackets, but others don't- mine didn't allow me to bring my jacket
).