Note: This article lists the technical specifications of the FIDO U2F Security Key. If you're looking for setup instructions for your Security Key, see https://www.yubico.com/start.
The FIDO U2F Security Key is FIDO Certified and provides the U2F application which is used by many popular services including Google, Dropbox, Facebook, Github, Duo, and many more.
Interface
The FIDO U2F Security Key uses a USB 2.0 interface.
Applications
U2F
The U2F application can hold an unlimited number of U2F credentials and is FIDO certified.
Physical Specifications
Form Factor
Connector: USB-A
Dimensions: 18mm x 45mm x 3.3mm
Weight: 3g
Temperatures
Operational range: 0 °C to 40 °C (32 °F to 104 °F)
Storage range: -20 °C to 85 °C (-4 °F to 185 °F)