This is the Almirian Crusader Helm.
https://wiki.spiralknights.com/Almirian_Crusader_Helm

It is shiny, it is beautiful and it is the original helmet of noble knights of Almire.

Now these are other crusader helmets.
https://wiki.spiralknights.com/Raging_Crusader_Helm#Raging_Crusader_Helm

Just duplicates from those endless boxes.

The problem is that Crusader Helms from boxes have all 4 slots for accessories, while the Real Almirian Crusader Helm has got only 3 of these. It lacks the helmet front slot, which is pretty sad, because many accessories of this type are very cool and some can fit the design of this Almirian Armor greatly.

Was it intentional to remove the Front slot from the original helmet? I don't know, but I suggest you to "return" this slot.