The MI 2N (French: Matériel d'Interconnexion à 2 Niveaux, English: two-level interconnection rolling stock) is a family of double-deck, dual-voltage electric multiple unit trainsets that are operated on the Réseau Express Régional (RER), a hybrid suburban commuter and rapid transit system serving Paris and its Île-de-France suburbs.

There are two variants of the MI 2N that look very similar but feature different motorization and interior layout: The trainsets were by a consortium of French manufacturer Alstom (at the time known as GEC Alstom) and Canadian conglomerate Bombardier.

The double-decker trains grew out of an effort to increase capacity on the RER A line, one of the world's busiest routes.

Having this capacity to transport more than 2600 passengers, which can be distinguished from the layout of the MI 2N trains, is the fact that they have 15 doors on each side, including 3 per car.

Having a width of 2m which allows to take out and input 4 people on such door namely the unit of the flow rate of users (voy.m3).