Hi, I’m Germano
I would like to make a 4-day pass (30/12 - 2/01) in 1 month only first class tickets for 3 night trains: (Venice - Vienna; Vienna - Berlin and Berlin - Zurich) and 2 regular trains (Milan - Venice; 30/12 and Zurich-Milan; 2/01)
If I do this type of pass, can I book any seat on any train (of Trenitalia railway company for regular trains and of OBB nightjet railway company for night trains) in those 4 days? even seats with couchettes or beds?
Thanks for the availability
Please note that in the Nightjets of OBB there is no difference in Travelclasses (this means you can book even with a 2nd Class Pass all Couchette or Sleeper offer 
) The reservations for Nightjet´s starts from 14€ for a Seat up to 150€ for a private Single Sleeper Compartment with private WC/Shower :)
You can reserve the Nightjet directly via oebb.at Here a manual how to Reserve Nightjets with a Railpass
Here just one Nighttrain with reservation fee examples Price Overview
I suggest to have a look for special fares (Saver Fares) as these workout mosttimes cheaper (Note that there exist a direct Nighttrain from Milan to Vienna )
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