One of the key features of Ironkey is Two-Factor Authentication.
Neil J. Rubenking of PCMag.com explains it as:
“A hacker armed with your bank account password can steal your money, but a hacker who just gets your ATM card PIN can’t withdraw a stack of twenties. Why? He doesn’t have the card itself. To get money from the ATM, you must have the card and know the PIN. This combination of “something you have” and “something you know” is a form of two-factor authentication.”
IronKey devices follow the same principle. To access the drive you need two things, the physical drive itself and the password. If you only have one of the two then you’re out of luck, you can’t access the data.