Lead B-TRAIN units are designed to carry a single 20′ container in either an open or closed configuration. Rear B-TRAIN units with back to dock capability are designed to carry either one 20′ or one 40′ container. Pick your model CCBL24-2S-00 CCBL24-2S-18 CCBL29-3S-00 CCBL40-3S-00 CCBR32-3-00 CCBR3240-3S-00 CCBR33-3-00 CCCOBL4010-3S-01 CCCOBL4010-3AS-01 CCSBL38-2A-00 CCSBR32-3A-00