I am thinking about buying a pair of physical 2FA keys to protect my password manager and sensitive accounts. Which brand and model do you suggest?

If a model with open source firmware doesn’t come with big drawbacks, I’d prefer it, because I may learn from the source code and even contribute to it.

NFC is not necessary, and the keys should be USB-A. A fingerprint reader is welcome if the price doesn’t increase too much.

Thank you all in advance.