Bronze domed shield boss or phalera

A phalera or shield boss of thin sheet bronze. A central domed disc is surrounded by a flat rim with a moulded edge. Along the rim are 25 moulded smaller circles, each with a central moulded dot. The central dome is concave with a tiny punched hole in the centre through which a small pointed rod of bronze was pushed to form a tiny loop and two pins on the reverse.