The buses on the historic K line aren't quite as old as the ones on Prague's nostalgic tram lines, which date back to the 1950s, but will be familiar to long-time residents of the Czech capital. The line is made up of six buses that date from the early-to-mid 2000s, including two Karos B951 models, two Karos B961s, an Irisbus Citybus 12M, and an Irisbus Citelis 12M.