Website: www.dashessenticket.de (German only)
Pass: Hes5en Ticket
Price: �30 at DB Automaten, on buses, and at ticket counters; no ticket for single person.
Valid for 2 - 5 people for unlimited travel all day (from 9 AM weekdays or midnight weekends until 3 AM the following day) on all regional trains (IRE, RE, RB) in Hessen in 2nd class. Valid for all transport (S/U-bahn, streetcars, buses) of most Verkehrverb�nde in Hesse.
Link to map of pass validity
Nordhessen (NVV)
Covers Hesse north of Fulda and Marburg. Includes Kassel and Wilhelmsh�he.
Covers most of Hesse south of and including Fulda and Marburg. Includes Frankfurt am Main and shares Mainz and Wiesbaden with the Rhein-Nahe district in Rheinland-Pfalz.