Goods also originate if they are produced entirely in Canada, Mexico and/or the United States exclusively from materials that are considered to be originating according to the terms of the Agreement.
A change to heading 41.04 from any other heading, except from heading 41.05 through 41.11.
The finished leather originates in Mexico because it meets the Annex 401 criterion. Assuming the eyeglass cases do not contain any non-originating materials, they originate since they are made wholly of a material that is originating (because the finished leather satisfied the Annex 401 criterion).