Obverse: VIRTVS PROBI AVG
Radiate, cuirassed and helmeted bust left, holding spear and shield.
Reverse: MARTI PACIF / I / QXXI
Mars walking left, holding olive-branch, spear and shield.
Bilon, diameter 20,3 x 21,0 mm, weight 3,62 g.
This coin is part of the famous coded Eqviti series (see the first letter "I" in left field, which is the 4th letter of the EQVITI word struck by the 4th officina, i.e. officina "Q"), discovered and first published by Alexander Missong in his articale ‘Gleichartig systemisirte Münzreihen unter Kaiser Probus’ (1873).