Low floor section with wide doors, for those with restricted mobility
Air conditioning
Stronger cab area for reduced crash damage
The trains can work in multiple of up to 3 sets.
X73813 - X73818 are former CFL (Luxembourg) units 2101 - 2106 and operate in the Alsace region. The SNCF Class X 73900 is an identical version of the X 73500, but can also operate into Germany.
TER livery - metallic grey with blue ends and TER logos. Most X 73500 carry this.
TER Bourgogne livery - metallic grey with red and yellow ends
TER Languedoc-Roussillon livery - metallic grey with red, yellow sun rays.
TER Champagne-Ardennes livery - metallic grey with yellow on the central part and the logo of the region.
X 73744 and X 73751 wear a special livery for the Andelot-en-Montagne - La Cluse railway
X 73752 - X 73755 have been fitted with Integra-Signum (Swiss Train Protection) and are used on the Besançon - Le Locle - La Chaux-de-Fonds service.
X 73809 with Poitou-Charentes region has been fitted with solar panels to its roof to power the electrical components of the train