Jon, that is a good question . I had to look at the last camera I built (the 11x14) so I could tell. It is glued to the frame on the inside. The back is very tight to the inside of the box and the front I'm going to make it like I did the 11x14 in which the bellows frame slides into place and then is secured with brass fittings like my Zone VI. Once you see it it is not to hard to do.