Librem Key
Yubikey
Purism sells a combination of the Librem Key and Librem laptops. They will configure everything and ship it. You then have the option to change the keys on the smart card to guarantee that even they cannot get into it. The theory is that we trust Purism to not install spyware on our hardware and we run only software which we also trust using encryption and signatures based on the Librem Key to prevent tampering.
I have a couple of keys. They can be used interchangeably on Librem laptops with some caveats. There is a counter on the key that the authentication tools use. When swapping keys the counter changes so you have to expect the auth to fail until the counter is reset in the auth process.
Most other functions can be done interchanging the two keys once both are setup and applied.
I have not used this much. It does not work the same way as the librem key. as a FIDO2 device it seems to be missing some of the features of the other