The Security Key by Yubico provides the FIDO2 application as well as the U2F application, allowing for greater flexibility.
The Security Key by Yubico uses a USB 2.0 interface. All applications are available over this interface.
The U2F application can hold an unlimited number of U2F credentials and is FIDO certified.
The FIDO2 application allows for secure 1FA and 2FA authentication and can store credentials, allowing for username-less login. Up to 25 resident credentials can be stored, with up to 3 of the credentials being RSA. The credentials on this application can be PIN protected for extra security.
Dimensions: 18mm x 45mm x 3.3mm
Operational range: 0 °C to 40 °C (32 °F to 104 °F)
Storage range: -20 °C to 85 °C (-4 °F to 185 °F)