Wikipedia
The Thraex (pl. thraeces), or Thracian, was a type of Roman gladiator, armed in the Thracian style with small rectangular, square or circular shield called a parmula (about 60 x 65 cm) and a very short sword with a slightly curved blade called a sica (like a small version of the Dacian falx), intended to maim an opponent's unarmoured back. His other armour included armoured greaves (necessitated by the smallness of the shield), a protector for his sword arm and shoulder, a protective belt above a loin cloth, and a helmet with a side plume, visor and high crest.
He and the hoplomachus, with his Greek equipment, were usually pitted against the murmillo, armed like a legionary, mimicking the opposition between Roman soldiers and their various enemies.