This mod add a new cavalry unit, the roman-byzantine Cataphract. For historical reason, the unit mantains his greek name (Kataphractos).
The Cataphract was an high-armoured and well-equipped oriental cavalry unit, characterized by a full armor for both man and horse.
The Cataphract was used by many oriental populations, like Persians, Sarmatians, Seleucids, and also by later Roman Empire and Byzantine Empire.
I added some screenshots at: