The Life-Like Trains 8471 HO Scale The Katy MKT 90186 Yellow Boxcar Freight Car is a pre-built model train boxcar made of plastic and metal. It is designed in a vibrant yellow color, with a length of 6 inches, specifically for HO scale model railroads. This ready-to-go freight car is a highly detailed replica that would make a great addition to any model railroad enthusiast's collection, adding a pop of color and realism to their layout.