like when fingerprints match

When a piece of a jigsaw puzzle fits into the right spot, you can say:

        Qay'mol mey (Qay'mol) teSra'  "the (puzzle) piece fits (into) the puzzle" (In this context, you don't have to repeat Qay'mol, but it's fine if you do.)

        or

        nelchu' Qay'mol teSra' "the puzzle piece fits perfectly"

The first focuses on the interlocking of the pieces; the second focuses on the piece in question occupying the identically shaped space where it goes.