I have 7 3/8 size head aka L. With the Poe helmet, I can fit but I need to reach in and pull those ear fabric pieces back in place. If I glued them all in place, it would be better. The stormtrooper helmet fits my head fine fit it hits the bridge of my nose. The Ren helmet is fine. I don’t have a Vader.
Can’t fit in the trooper, kylo my chin is out, Poe I can fit if I remove everything inside, but it’s still why too tight for comfort. Vader is still inside the amazon shipping box lol never tried it