Originally posted by sterretje See above, the Katzeye's are the same for K100D and K-r so it should work. Any reason why not? Maybe you're mistaken with the K10D/K20D versus K7/K5 ?
Definitely possible I'm mistaken on that. There's contradictory information out there (and most of it is from focusing screen vendors). Katzeye lists those models together, every other site I've seen splits them up. I'd say ask Pentax, or someone at Katzeye, before buying one (especially from other vendors, as one that isn't listed for the K-r on the vendor site isn't going to get much support if something goes wrong).
I'd also search about potential shimming issues for the one I planned to buy. It would be best to have a few on hand before installing, a 0.2mm and a 0.4mm especially (unless you don't mind DIY with a bit of tape or something).