Class Z23500 is a class of railway electric multiple units operated in France. They were built by Alstom and Ateliers du Nord de la France, (which became Bombardier) for SNCF and are used on the TER Network. These sets consist of 2 double deck coaches. They were built from 1997 and a total of 80 units were built. The units were ordered by the following regions: Provence-Alpes-Côte d'Azur, Nord-Pas-de-Calais and Rhône-Alpes. They are mainly used on stopping services around the French Riviera (Provence-Alpes-Côte d'Azur), Lille (Nord-Pas-de-Calais) and Lyon (Rhône-Alpes).They are all in the TER livery, which is a Blue Front in a diagonal line with a metallic grey side. However the Rhône-Alpes units have green and purple sides with Rhône-Alpes written on the side in Large writing.