all original 19th century antique american interior residential passage size doorknobs patented and fabricated by the chicago hardware company, chicago, il. each doorknob contains a tightly affixed oversized iron shank designed specifically to accommodate the chicago-niles mortise lock. the "screwless spindle" doorknobs are comprised of fired red clay with a jet black porcelain enameled finish. very common among 19th century chicago homes. priced for the pair. locks and escutcheons available. measure approximately 2 1/4 inches in diameter.