In June 2016, RhB announced it had signed a contract with Stadler Rail for 27 four-car metre-gauge EMUs. This original contract also included options for up to 20 additional vehicles. At that moment, it is the largest rolling stock procurement project in the history of the RhB.

In 2017 RhB decided to procure nine extra trainsets (now 36 in total) of the Capricorn, the name that was given to this type of trains later on.

On 15.04.2019 the first train was officially presented (fleet number 3112). With the new trains RhB will be able to introduce portion working on lines such as Landquart – Klosters – Davos/St. Moritz – resulting in a half-hourly cycle on single-track routes without costly line extensions.