All trains plus many local transit options as well. It's usually valid in most bigger cities. My ex-ex-employer had given me one and I've used it many years. In

All trains plus many local transit options as well. It's usually valid in most bigger cities. My ex-ex-employer had given me one and I've used it many years. Incredibly liberating when you have the ability to hop onto any train and just sit. Reservations were sometimes problematic because popular trains had little amount of not-reserved free seats but Bahn.Comfort seats usually saved the day.