Porelon 11471 H Series Smith Corona Correctable Mylar Typewriter Ribbon, 6-Pack Compatible correctable mylar typewriter ribbon, replaces manufacturers part #'s 21000, 21010, 21500, 59436, and 67108 Vivid and consistent black color Exceptional light fastness and durable impressions Designed to operate with original equipment identified, and will not void equipment warranty One year (12 months) warranty