Stadler markets double-decker electric multiple units under the name “KISS” (“komfortabler innovativer spurtstarker S-Bahn-Zug” - “comfortable, innovative, high-acceleration S-Bahn train”), which were originally developed for commuter traffic. Variants have now also been sold for regional and intercity transport, which have a top speed of 160 to 200 km/h and consist of three to seven cars. Depending on the version, the powered bogies are distributed differently across the train and each have two traction motors with 500 or 750 kW each. Recently, diesel-electric and battery-powered variants have also been developed.

So far, customers have come from eleven countries, most of them from Europe. However, there is also the “Eurasia” version, which is designed for Russian broad gauge and takes full advantage of the larger loading gauge there. A variant with more angular shapes and a larger number of traction motors was developed for the US customer Caltrain. Depending on the customer, the trains are manufactured in Switzerland, Germany, Belarus, Poland or the USA.