There are many Yasikor lenses that are 4 element, Yashica switched some where in the middle of the production without renaming them. They later switched design slightly and renamed the lenses as Yashinons. I have owned Yashica D's with all three variants and after stopping down a couple of steps, are almost undistinguishable between them. I have also had the LM modle with a 4 element Yashikor and it was a good performer.