Thanks David B. haven t had a problem yet with that....these backs are labeled FOCUS and have windows for 6 x 9, 6 x 12 and 6 x 17...I am sure they are similar....for me I had to master the putting the back on with the springs snaps but have it down pretty well....I am happy with the back, did a lot of NYC street scenes with it as well as the center photo of the APUG flyer Blaze-ON produced for the silver convention...the Brooklyn bridge shot ..for what they are used for and the price they are ok actually, one Apugger posted upgrading the light seal an easy enough task and available...in the past I imported and sold a lot of Russian optics and scopes....this looks like a good product for the money....I have used and tested several of the Focus products for about 12 months now...my present family situation has taken a big change and I will now probably not be making any new ventures in the near future, so that is why I have mentioned these test demo models I have at the present...I had 4 of the 7 x 17 left as of this morning, I now have 2 of the 7 x 17 s left, they work and are new, as is in the box shipped in the U.S., 453.00 loaded with your choice of AGFA APX 100 or 400 expiration date Jan. 01, 2009....yep a stash of the last batch!
Cheers,
Dave in Vegas