Thrall introduced a new five-unit articulated well car in 1983, equipped with interbox connectors (IBCs) to lock containers on the car using the four corner castings. By the late 1980s, longer 45 and 48' containers were in service, and the design was again reworked to accommodate these heavier loafs in the middle wells. The latest version (which is the prototype for this kit) has additional reinforcements and IBCs to carry everything from a pair of 20' container up to a single 48' container in any of the wells. These ready-to-run models feature authentically painted die-cast metal bodies for maximum weight and performance.