The K-class Fast Express is a conventional fast train in China, marked by a 'K' prefix on timetables and linking many regional cities with regular stops. These trains are not bullet trains but run at speeds up to about 120 km/h and offer seats and sleepers in different class options, such as hard seat, soft seat, hard sleeper, and soft sleeper for a longer trip. For travel planning, Rail Monsters sells K-class tickets online with booking tools to compare routes and prices, check seats and class options, and book your trip in advance.