Model: This is an advanced model building kit as a simulation of a straight truss bridge design in metal construction. This is a version in very sturdy, precise laser-cut architectural cardstock and MDF board. The steel bridge girders have rivet engraving and gusset plates. The maintenance walkway has the look of wooden planks with railings. The bridge can take one (1) each 5903 and 5917 straight track. Bridge dimensions L 450 mm x W 152 mm x H 122 mm / L 17-3/4" x W 6" x H 4-13/16".