Scania N-series is a series of city bus with straight-up, transversely mounted Euro IV/Euro V engine at the rear. It is available as N230UB, N270UB (4x2 single decker) as well as the N230UD and N270UD (4x2 double decker). The double-deck variant is mainly built for use in the United Kingdom, and is available with Optare OmniDekka, Optare Olympus and Alexander Dennis Enviro400 bodywork, it can also be fitted with Scania's own bodywork and sold as the OmniCity.