This is a Union Pacific “City Of Denver” Streamliner Passenger Train Set. Set includes a 636W streamliner locomotive, two 637 passenger cars and one 638 observation car plus 3 vestibules. Sale includes its 636W engine box. Box is solid with one end missing its flaps. Set is an O gauge from the 1930s. Set has been sitting for some time and it ran last time I used it, but it could use a tune up and cleaning. Color scheme is a desirable brown and yellow. A fair amount of play wear and loss of finish from use.