This coin is part of an unpublished, very rare and brief first phase of Serdica's 3rd issue with greek letters and without the KA mark in exergue (Pink only cites latin letters which apparently were used in the second phase of this issue).
This is only the 3rd specimen of this type known; Ex. M. Griffiths collection
Virtually as struck with full original silvering and great details.
Obverse: IMP C M AVR PROBVS P AVG
Reverse: SOLI INVICTO = Sol in spread quadriga, holding whip
BUST TYPE: H2 = radiate bust left in consular robe, holding eagle-tipped sceptre (scipio)
FIELD / EXERGUE MARKS: -/-//Delta
WEIGHT 3.96g / AXIS: 12h / DIAMETER: 21-22mm
