Roman ridge helmets can be classified into two types of skull construction: bipartite and quadripartite, also referred to as Intercisa-type and Berkasovo-type, respectively.
The second type of helmet has a quadripartite construction, characterized by a four-piece bowl connected by a central ridge, with two plates (connected by a reinforcing band) on each side of the ridge, and a base-ring uniting the elements of the skull at the rim of the helmet; this type is further characterised by large cheekpieces.
[5] There are notable exceptions to this classification method, which include the Iatrus and Worms helmets, which have large cheekpieces and a base ring respectively.
[7] The amount of silver and gold used in the sheathing was officially graded by rank and was sometimes inscribed on the helmet.
[10] For a number of extant helmets, all that remains is the decorative silver or gold sheathing, the iron having corroded away entirely.
A similar helmet found at Augst has three slots in its ridge for the attachment of a separate crest.
[14] Late Roman ridge helmets are depicted for the first time on coins of Constantine the Great and are believed to have come into use between 270 and 300 AD.