PROBUS , ( 276 - 282 ) AE Antoninianus 

IMP CM AVR PROBVS AVG, radiate, cuirassed bust right.
AEQVITAS AVG, Aequitas standing left, holding scales and 
cornucopiae.
Mintmark XXI

RIC V-2 Rome 150, rated Scarce.

With permission of cgb.fr, Sept. 2009