ICA Dresden Reflex 8.5x11cm ??

I just got an ICA Dresden reflex camera and I'm confuse about the plate size it uses. Its too small to be 9x12cm and too big to be 6.5x9. I saw an auction where someone was talking about a 8.5x11cm size. Do you think this is correct? Was there such a size? I'd love to find some of those single sided metal plate/film holders for it - hint hint
thank you,
Robert

Are you confusing modern 9x12 holders which have the same outside dimensions as 5"x4" holders with the older pre WW11 9x12 holders.

If your Ica is an Avus type camera then it will almost certainly be a 9x12.

Ian