I've never seen or read about this film holder before, but I'm sure someone in APUG'land has. I've asked a couple of old time large format photographers here in Oklahoma, but they haven't seen one of these either. The septum (lower left) looks like it holds a 3.25x4.25" (80x105 mm) film, which goes into a holder (lower right) that has a swing arm to lock the septum in place. The ensemble goes into a folding case (upper right), and it looks like it just holds one of these at a time. The dark slide is on the upper left. The case is similar to a Graphic 1234 film pack holder, and the septum is similar to a Graphic 1268 (just smaller). The similarity with the two aforementioned Graphic backs would make me think this is a Graflex concoction. There are no markings on the case that would indicate its manufacturer, or its intended camera.