The Triumph of Probus

Reverse:
SOLI INVICTO, R * G in exergue. Sol in quadriga facing left with galloping horses. The four heads and sixteen hooves juxtaposed and rendered in relief create a sense of speed and power. Worship of the Invincible Sun was a military cult quite popular during the late Third Century and several emperors issued coins bearing SOLI INVICTO references.

Obverse:
IMP PROBVS AVG Draped and cuirassed bust of Probus facing left.

The coin is listed in David Sear's Roman Coins and their Values as s3379.