Atlas Model Railroad Company produces 3 levels of HO scale engines and locomotives.  The Master Line, the Classic Series, and the Trainman series.  Atlas Master Line locomotives and rolling stock are highly detailed models that faithfully recreate the prototype down to the paint scheme and even railroad-specific details.  Atlas Classic locomotives are created from retooled molds that produced some of the original Atlas products and, while less detailed than the Master Line, still hew closely to the prototypes they were created to represent.  Atlas Trainman® locomotives and rolling stock are less detailed than Atlas Master products but feature rugged construction and molded parts and a budget-friendly price that makes them great for modelers of all ages.