4-6-6 panel Youngstown improved style corrugated door used by many railroads. Commonly seen on boxcars manufactured between 1948 and 1952, but appeared on newly built cars as late as 1958. Injection molded in styrene plastic with separate tackboards. Fits HO scale Intermountain and Red Caboose boxcars with 6' door openings and 10' 0" interior heights.