The Baureihe 420 is a light - weight commuter electric multiple unit developed for the S - Bahn networks in Germany .
The Baureihe 420 was originally commissioned by the Deutsche Bundesbahn for the Munich S - Bahn , Stuttgart S - Bahn and Frankfurt S - Bahn networks .
The Baureihe 420 is a light - weight commuter electric multiple unit developed for the S - Bahn networks in Germany and was originally commissioned by the Deutsche Bundesbahn for the Munich S - Bahn , Stuttgart S - Bahn and Frankfurt S - Bahn networks .