Da-Yi 6x17 Roll Film Back for 4x5 Camera w/Int'l Back $475 or best reasonable offer This is the 6x17 back that you can use on a 4x5 with a Graflock or International back. It comes with a bellows viewer. It also comes with masks which enable you to take photos in 6x14 or 6x12 formats. The bellows viewer has a gridded ground glass. On top of that -- on the side facing the photographer -- I put a piece of a "reading lens", which is a cheap plastic fresnel lens available at office supply stores, which vastly improves the view when using a wide angle lens. The whole kit is in excellent lightly-used condition. I believe I've put fewer than 50 rolls through it; the rest of the time it's resided in a closed camera backpack, so it's clean and dust-free and ready to use. It was shipped to me missing one screw to hold the thick plate that mounts on the camera back, onto the body of the back, but this has caused no problems at all. There are plenty of other screws doing this same job, and there is no looseness, and no light leaks. The film chamber extends back about 42-43mm from the usual focal plane on the camera, so add this to the focal length of the shortest lens you can use on your camera, and you'll have the shortest focal length you'll be able to use on that camera with this back. The shortest lens I've been able to use is a 90mm on the Crown Graphic on which I used this back.. I don't recall, but I believe that about the longest lens you can use without it vignetting at 6x17 would be around 180mm or so. 210mm definitely vignettes slightly at the edges. The whole kit weighs about 3-1/4 lbs, so figure 4-1/2 lbs shipping weight from Zip Code 90027. Please Note: I wait for PayPal to clear to my bank account before shipping. This takes about 3 days.