While several types of loricae (armor) existed in the Roman legion, the lorica plumata was reserved for the use of military leaders (Tribunes and above, but typically Generals) due to the high cost of production, and maintenance. The name the Romans used for this type of armor is not known, lorica plumata being a descriptive term applied by modern scholars, referring to its resemblance to a bird's plumage.

The lorica plumata was basically a mail

Mail (armour)

Mail is a type of armour consisting of small metal rings linked together in a pattern to form a mesh.-History:Mail was a highly successful type of armour and was used by nearly every metalworking culture....

 shirt (hamata

Lorica hamata

The lorica hamata is a type of mail armour used by the Roman Republic and the Roman Empire. During the 1st century it was starting to be supplemented by lorica segmentata, but had been reintroduced as sole standard-issue armor by the 4th century. It was issued for both primary Legionary and...

) with small feather-like scales (plumes) attached to the rings. Requiring skilled labor and much time to create, this would have been an expensive piece of military equipment. And while many contest its utility on the field, it might have been used by Roman leaders due to its impressive appearance and its possible impact on the morale of soldiers.