Avant is a high-speed, medium-distance passenger transport rail service, operated in Spain by the Spanish public company Renfe. Avant services circulate at a maximum speed of 250 km/h, compared to the 300 km/h maximum speed of the AVE service. Their routes usually cover different provinces within the same autonomous community or between neighboring ones. Regional services at conventional speed are called Renfe Media Distancia.
Avant services are carried out by series 104, 114 and 121 trainsets, in a single class configuration without a cafeteria. From Wikipedia
