I am unable to verify what firmware version. The unit is sealed and about 3 years old.New Yubico YubiKey. 5 NFC is a premium multi-protocol hardware security key designed to protect your digital accounts from phishing and account takeovers. It provides seamless authentication across laptops, desktops, and mobile devices using both USB and NFC technologies.How it WorksUSB: Plug it directly into your computer or mobile device's USB port and tap the gold contact.NFC (Near Field Communication): Tap the key to the back of your NFC-enabled smartphone (iOS or Android) for frictionless authentication.Top FeaturesMulti-Protocol Support: Secures 1,000+ accounts including Google, Microsoft, Apple, and leading password managers. It supports FIDO2 (hardware-bound passkeys), FIDO U2F, Yubico OTP, OATH-TOTP/HOTP, OpenPGP, and Smart Card (PIV).Passwordless Login: Use it as a FIDO2 passkey to log in securely without entering your username or password.Extreme Durability: Water-resistant and crush-resistant with an IP68 rating. It requires no batteries or network connectivity.