The Biel–Täuffelen–Ins-Bahn near Bern, Switzerland was looking for a lighter train model to replace its aging fleet, so that a low-floor system does not require heavy installations on the roof.

The rolling stock for Mittelthurgau was later expanded to ten GTW 2/6 units (built 1998–1999) that are now part of the THURBO fleet (the three prototypes were sold to Italy).

The next lots were produced in meter gauge and were delivered to the BTI-Bahn and the CEV-Bahn (Chemins de fer électriques Veveysans) in 1997 – although the BTI-Bahn was first to order any GTWs with its seven trains, the CEV-Bahn ordered the biggest lot of the first generation with twenty trains.

In 1998 the Linzer Lokalbahn (Austria) placed an order which needed to be modified to conform to the DIN 5510 class 2 safety standard, as well as different electrification.

The full series were then manufactured at the new Stadler Pankow (Berlin) facilities being built in 2000 by a joint venture with ADtranz.

These follow the DB design being produced since 2000 for other customers as well, for example a batch of 12 trains went to Athens (Greece) in meter gauge (ordered in 1999, delivered since 2003).

As a consequence, the manufacturer saw its biggest customers, Arriva and Connexxion, switch over to the FLIRT models for the following deliveries in 2012.

Like Stadler's GTW family of multiple units, WINK has a central power module containing the energy generation, traction and auxiliary systems, while the frame and other parts are derived from the FLIRT models.

All of the usual comforts to be expected in a modern local network railcar are provided, such as air conditioning, a multi-purpose room, vacuum toilets (in a washroom suitable for the disabled) and a passenger information system.

This has led to actual restrictions when leaves are on the rails as the wheel slide protection can not fully compensate the effect.

[2] In Greece, Hellenic Train operates two variants of the Stadler GTW 2/6 (known also incorrectly as railbus), owned by OSE.

The metric gauge variant (OSE class 4501) operates in the Suburban of Patras (Proastiakos) and the tourist line of Katakolo – Pyrgos – Ancient Olympia.

The standard gauge variant (OSE class 560) operates on the regional service Athens–Lianokladi and the local Lianokladi–Lamia–Stylida line (which is referred to as Proastiakos Lamias).

In Italy GTW are used by some regional railways, and called ATR: The multinational transport company Arriva uses the diesels on the lines: Leer (Germany) – Groningen, Delfzijl–Groningen, Leeuwarden–Groningen, Roodeschool/Eemshaven–Sauwerd, Veendam–Zuidbroek, Leeuwarden–Stavoren, Leeuwarden – Harlingen Haven.

The electrified GTW are used on the lines Dordrecht – Gorinchem – Geldermalsen (since 2018 by transport company Qbuzz) and since December 2012 also on Zwolle – Emmen.

Since December 2022 electrified GTW's are also used on the weekly Arriva night train service between Groningen and Schiphol Airport.

Additionally, the Nuria trains have a second pantograph in the front car to remove ice and snow from the overhead wires on colder seasons.

[8] The 4 newer units feature LED destination signs instead of flip-dot signs, a slightly tweaked paint scheme (to better match the MetroBus paint scheme), and an updated engine car design that features a rounded top rather than an angular top as found on the older DMUs.