What kind of stress test do you have in mind? I've had a yubikey 4 for almost two years on my keyring that I use daily and despite not taking very good care of

What kind of stress test do you have in mind? I've had a yubikey 4 for almost two years on my keyring that I use daily and despite not taking very good care of it it still works fine. It's been wet, it's been scratched, it's supported the weight of my keys while hanging from a USB port, it's been plugged and unplugged thousands of times... They're pretty sturdy. Of course if you take some pliers to them I have no doubt that you'll be able to break them in half but for normal use you won't have a problem IMO. The size doesn't bother me either, it's like a very flat USB key. I also have a nitrokey that's a bit shorter and bulkier and it comes with a cap which might be better to protect the connector, but on the other hand I'm sure I'd lose it sooner or later. A retractable port or something similar would probably be a better idea. Also the nitrokey is significantly slower which is the main reason I only have it as a backup for my yubikey currently.