You have the choice to add one or more fingerprints to add an additional security layer to the mandatory PIN code. You can enable fingerprints for both unlocking your ZERO and/or signing transactions.
To manage your fingerprints, go from the ZERO dashboard to Settings → Device protection → Manage fingerprints. You can add up to 5 fingerprints
To configure how you want to use your fingerprints, go from the ZERO dashboard to Settings → Device protection → 2-factor authentication. You can require a fingerprint for unlocking your ZERO and/or for signing transactions.
Yes. You can add up to 5 fingerprints from any person. Each of those 5 fingerprints will be able to to unlock your ZERO and to sign transactions. At this moment it is not possible to configure specific fingerprints to be required.