Very little of this helmet remains. In particular, the back of the helmet has not survived and this makes it almost impossible to assign a type with any confidence, other than to say what it is not.
The ear guards have obviously been forced out from the helmet skull. However, there are holes clearly intended to house rivets, which would have been used to attach additional ear protection made from copper alloy castings or sheet material.
The helmet appears to have been made from copper alloy, which would eliminate those types made from iron.
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