Tom Frenette

I'll have to get back to you with exact measurements when I'm near my camera. I did save the attached photo however. The original ring from the viewfinder (IIA&IIB Models) that secures the older eye cup sits perfectly in place, but not wide enough to hold the rubber on of course. If you've got the diameter of that ring, it should give you an idea.

The link above looks like the correct one for the IIA. I ended up purchasing a slightly larger version for my IIB in the past, but was able to mount it by adding a thin washer in between the screw on ring and eye piece. If for some reason it doesn't fit perfectly, just find a washer at a hardware store.

I found this from an Arriflex iiC manual on ebay. 28mm Standard mount is the widest focal length that won't protrude too far, other than the exceptions listed.

Hey Phillip, The only information I was able to find on it was in the manual. Not an exact answer on how to get it to fit, only that it needed to be sent to the factory.