In France and the EU, for FREIGHT, the recommended couplers are FRET+CG (references R.401 in x4 and R.405 in x24).

For VTU, Corail, and passenger coaches from eras IV-V and VI, it is recommended to use VTU references (R.403 in x4 and R.407 in x24) and Loco-VTU references (R.404) for coupling coaches to locomotives (see dedicated question).

You can consult the dedicated coupler page or contact support for additional information :)

Although the coupling attaches to the NEM pocket, it is possible to couple and uncouple with a single motion (like a railcar) without turning over the train while maintaining good traction: it is possible to pull approximately 1kg without the coupling accidentally detaching.

Inter-VTU couplings (R.403 and R.407) allow coaches to be coupled together, while Loco-VTU couplings allow the trainset to be coupled to a locomotive.

These couplings are interchangeable and compatible; you can certainly use Inter-VTU couplings between a trainset and a locomotive. Loco-VTU couplings are simply a variation with the connecting components aligned with those of the locomotive for greater realism, intended for the most discerning eyes.

As the coupling is made of a single piece, unlike the couplings on the market which work in pairs.

A pack of 4 Raility couplings can connect 5 elements (since only one piece connects each element).

A pack of 4 couplings sold commercially can connect 3 elements (because two couplings are needed to connect two elements).

They are printed in high-resolution resin (16k allowing details of <0.02 mm) and high strength (ABS-Like Pro 2).

They obviously remain fragile if you try to twist, bend, or break them. However, they remain perfectly resistant for normal use (handling, pulling, etc.).

The most stressful part for the pieces is transportation, which is why Inter-VTU and Loco-VTU type couplings are shipped with additional couplings in case of breakage by the carrier.