I can’t find the THE industries helmets anywhere in XXL
Try whatever the biggest is, IME if the helemts the right shape even a size down fits snug rather than not fitting at all.
Have you been into a shop or are you trying to buy online? There’s definately difference is the measurements between brands, some are fine some really aren’t and my head’s so big I’ve never had a motorcycle helmet that’s been comfortable for more than an hour (with the exception of one cheap chinese one that was dirt cheep to the point i didn’t trust it!).