They are formed of two power cars (8,800 kW (11,801 hp) under 25 kV—like the TGV Atlantique) and eight carriages, giving a capacity of 377 seats.

The dual-voltage sets weigh 383 tonnes (844,370 lb), and owing to axle-load restrictions in Belgium the triple-voltage sets have a series of modifications, such as the replacement of steel with aluminium and hollow axles, to reduce the weight to under 17 t (16.7 long tons; 18.7 short tons) per axle.

Owing to early complaints of uncomfortable pressure changes when entering tunnels[citation needed] at high speed on the LGV Atlantique, the Réseau sets are pressure-sealed.

After some ten years of successful service, the interior of TGV Réseau sets became outdated and needed a refurbishment.

This refurbishment was part of the TGV Est project, as the dual-voltage sets were to assure the domestic services there.