The cheap keys support way less features. The are simple U2F tokens and cant do anything else. The others support tons of other features. You can use them for

The cheap keys support way less features. The are simple U2F tokens and cant do anything else. The others support tons of other features. You can use them for classic 2FA with OTP (TOPT/HOTP/YubiCloud OTP). They support using your Yubikey as a Smartcard, you can put your 4k GPG key setup into your Yubikey. They also support the PIV interface and you can use it for lots of different operations, like code signing, certificate authority, windows authentication and more. Some of the sticks support NFC. This means you can use Smartcard, PIV and U2F over NFC. Sadly at the moment they have no key that supports 4k GPG Keys AND NFC. However they will update this soonish. See: https://www.yubico.com/products/yubikey-hardware/ https://www.yubico.com/products/yubikey-hardware/ There are also older models that you can still buy that don't support U2F at all. > Are there other keys than from Yubico recommended? Their are others, just search for U2F on amazon, seems their are at least 4 companies implementing them. Nitrokey is a pretty cool company with a interesting option that are somewhat different from Yubikey.