From Citizen Sleeper Wiki
Sabine's Passkey is an item players encounter throughout gameplay of Citizen Sleeper. It's primary use is to unlock unit 207-F.
Description[edit]
The Passkey belongs to Sabine and is handed to the Sleeper wrapped around a Stabilizer vial by Sabine. The passkey can be used further to unlock Unit 207-F which will allow players to continue with Sabine's questline and complete further clocks.