In the "Extended Vision" or "Wide Vision" caboose, the sides of the cupola project beyond the side of the carbody. Rock Island created some of these by rebuilding some standard cupola cabooses with windowed extensions applied to the sides of the cupola itself, but by far the greatest number have the entire cupola compartment enlarged. This model was introduced by the International Car Company and saw service on most U.S. railroads. The expanded cupola allowed the crew to see past the top of the taller cars that began to appear after World War II and also increased the roominess of the cupola area.