[Cryptography] Encrypted flash drives: Secure?

[Erik]

I'm looking at some of the encrypted flash drives on the market, and one
from Corsair features all-hardware encryption with a pin-pad physically
located on the flash drive.


https://www.corsair.com/en-us/flash-padlock-2-8gb-usb-flash-drive-refurbished


Anyone know whether these actually offer the security that one would
expect from a dedicated device? They have 256-bit AES encryption, and as
far as I can tell there are no drivers at all for the device, so it all
exists on the flash drive itself, but what's the keyspace on these
things? Would it be a good place to store my private keys, for instance?