four matching c. 1900's american antique interior residential passage door backplates likely fabricated by the penn hardware company, reading, pa. the lot of matching doorknob backplates are comprised of stamped steel, with traces of the original copper-plated finish intact. each backplate contains a single keyhole, protruding collar and screw holes for mounting purposes. measure 5 1/4 x 1 1/2 inches. priced for the lot of four.