I just love this as a found object, complete unto itself, perfectly framing and holding within it all of the dynamics and resonance of the "exposed" stamped on its face --indeed, it feels very much like the encapsulation of a peep show, with black shades blocking glass windows! Two latches on the side turn to allow the black cards to slide out (there are two of them, one on either side), revealing two glass plates still inside. And looking closely, once can see "Plate No. One" and "Plate No.2" hand-lettered in graphite against the black. 

6 5/8" x 4 3/4" and in very good antique condition. Slides open and closed pretty easily.