different style freehub?
 

On my old 2001 Diamondback Response, I wanted to remove the freehub and clean/lube it since it's stiff and I'm into the rear bearings. However, when looking inside of the hub I don't see the hex pattern to remove it with an Allen key.

I've tried pulling on it, however it seems stubborn, either threaded on or seized. Any words of advice since the rest of the wheel is in pretty good shape?

Edit: It removes with a 12mm Allen, there was so much grease inside and it was so darkened that I couldn't see where it would take an allen.
My local bike shop enlightened me on this before trying to find a 12mm around, before finally finding a clearanced one at Tractor Supply while I was getting cat food.