This is the history of the Brescia-based automobile manufacturer, "O.M.," from its origins with the "Zust" company up until the end of car production in the mid-1930s. All the models are presented in different mechanical and coachwork specification. An important section concerns the company’s manifold racing results, first with the "Mille Miglia" and then in various competitions held in Britain and the United States. To complete the volume a detailed list is presented of all the O.M. sporting successes.