In 1944 the car sides changed over to mid-rib style with flat areas at each end. This Accurail kit is based on the original cars which operated into the early 1980s. This boxcar kit features a one-piece detailed injection-molded body with most details molded in place for durability during operation. Other features include realistic decoration with end reporting marks (on decorated models), underbody details, trucks with slippery plastic wheelsets, nonmagnetic axles and AccuMate(R) magnetic knuckle couplers. The 40' Rib-Side Boxcar kit is great for modelers of all skill levels and includes complete instructions.