The FIDO2 specification states that an Authenticator Attestation GUID (AAGUID) must be provided during attestation. An AAGUID is a 128-bit identifier indicating the type of the authenticator.

New AAGUIDs will be issued for new YubiKey products which support FIDO2, or when existing YubiKey products have FIDO2 features added or removed.

For the complete list of AAGUIDs, see