The HO Athearn RTR 7221 ATSF Santa Fe 54' ACF Centerflow Covered Hopper 307135 is a pre-built model train hopper car in 1:87 scale. It features a gray color and is made of plastic/metal materials. The hopper is branded as ATSF Santa Fe and comes with painted details. This ready-to-go hopper car is perfect for collectors and hobbyists looking to enhance their model railroad layouts with a high-quality, detailed addition to their collection.