Thetis FIDO2 Security Key (folding USB-A) review

This is a folding USB-A security key from Thetis. The research is mixed on what this exact model supports, so the listing details matter before you buy. Thetis lists FIDO2 and FIDO U2F for its PRO model. One Thetis page describes the USB-A folding model as U2F-only. If you want passkeys, check that the listing you are buying names FIDO2.

The key needs no batteries or network connectivity. Thetis gives a one-year manufacturer warranty.

For the PRO model, Thetis lists FIDO2 and FIDO U2F, plus 50 OATH slots. The research does not list PIV smart card or OpenPGP support, so don't assume either. The FIDO2 listing is stated for the PRO model, and the research does not clearly extend it to the folding USB-A version. That uncertainty is the main thing to resolve. Until the listing confirms FIDO2, treat the folding model as a U2F key.

The folding listing is USB-A. The PRO model adds USB-C and NFC, but those belong to a different model. The research also notes that NFC works only through mobile authentication, not on macOS or Windows.

With USB-A as the only connector listed for this version, it suits desktops and laptops with USB-A ports. It is a weaker match for USB-C-only laptops, and the research lists no NFC for phones on this model.

Thetis lists 200 passkey slots for its PRO and PRO-A models, along with 50 OATH slots. The research doesn't state the passkey count for the folding USB-A model specifically. If the folding version matches the PRO-A figure, storage would not be a limit for most people. Confirm that on the listing rather than assume it.

The research gives FIDO2 L1 for the PRO model. Thetis does not list FIPS. The research says nothing about whether the firmware is open-source or updatable, and it records no vendor security advisories either way.

That leaves little to judge on the firmware side. If certification beyond FIDO2 L1 or a clear update policy matters to you, the available information doesn't answer it.

The body is aluminium alloy. A Thetis PRO 2-pack page describes the key as water-, crush- and tamper-resistant. A third-party review says the electronics are not completely waterproof. Because those two accounts differ, the water resistance claim is best treated with caution. The one-year warranty is the only firm durability commitment in the research.

Thetis sells its PRO key in 2-packs. That suits anyone who wants a spare key registered alongside the main one.

Owner feedback in the research is short. Two themes recur: PIN setup is easy, and the management app is useful. Owners also describe the key as good value for money. The research doesn't give owner reports on long-term durability or on compatibility across services.

With USB-A as the listed connector and a FIDO2 claim that is clearest for the PRO model, this key fits a narrow job: a USB-A second factor for machines that have the port. The research lists USB-C and NFC for the PRO model, and 200 passkey slots for the PRO and PRO-A models, but does not state them for this folding listing. If you need those, read the PRO listings instead. If you only need a plain USB-A key and you confirm the protocol support first, owner comments on PIN setup, the management app and value are the main points in its favour.