Originally posted by rvannatta At least with the english translation, it is not possible to determine what you are selling.
One cannot determine if it is a Pentax product and if so what or a third party product that fits some pentax model product....
If it is a RefConvertor A, then it is in fact a Pentax (Asahi Optical) product. It is a right angle finder with a 2x setting.
There was an M and and A and both will work on all M and newer series cameras including dSLR bodies. The only difference in the A and M is that the A has a slightly broader field of view to see the lcd in the viewfinder. These are relatively hard to come by and are helpful in macro photography. I have the M version.
Edit: Go here and scroll down the bottom for links on various right angle finders by Pentax.
http://kmp.bdimitrov.de/misc/focus/index.html
And go here for a review of the Refconverter A.
https://www.pentaxforums.com/accessoryreviews/pentax-refconverter.html