Watch List notes:

Probus Æ Antoninianus. Serdica, AD 277. IMP C M AVR PROBVS AVG, radiate and mantled bust left, holding eagle tipped sceptre / SOLI INVICTO, Sol in spread quadriga, holding whip; KA•Γ• in exergue. Cf. RIC 862 & 865. 3.79g, 24mm, 12h.

Near Extremely Fine. Partially silvered. This mintmark is not listed in conjunction with this obverse legend in RIC.
Rare Variant not in RIC