Hello KasiaM
Thank you for your question.
It depends on many zones of ZVV you already have included in your travelcard and also which connection are you taking.
If you have a ZVV only travelcard, but you want to travel in a Z-Pass region (this means ZVV+Ostwind / ZVV+Schwyz Zug / ZVV+A-Welle), you need a Z-Pass ticket. It means the ticket has to start in the ZVV region and end in the Schwyz/Zug region.
In your case, you buy a ticket from the last train stop in your last ZVV zone to your final destination in the Schwyz/Zug zone.
Specifically, if your ZVV travelcard is valid up to zone 152, you buy a ticket from Wädenswil to Einsiedeln, for a total of 5 zones (152, 153, 181, 679, 680).
For any other question please call pur colleagues at the SBB Contact Center (0848 44 66 88, CHF0.08/min): they will be able to give you a personalized answer, based on you travelcard and your chosen connection.
I wish you a good day and a happy New Year.
Regards,
EleonoraS