Wearing a cuirass.
The cuirass is body armour - a breast plate covering the front of the upper body, made of leather or other material. These were later augmented with sewn-on disks of metal, rings, and the like. Kings and emperors are often shown on their coins wearing an elaborately ornamented cuirass. Eventually the base material was made of metal instead of leather, and the back was also covered, hence the reference to a "pair."