Antoninus Pius (138-161 A.D.) - Brass Sestertius - 32mm, 24.94gr
Obverse - ANTONINVS AVG PIVS PP TR P XVIII
Antoninus, his laureate head right.
Reverse - LIBERTAS COS IIII, SC
Libertas standing left, holding pileus and scepter.

Minted in Rome 154-155 A.D. (TRP XVIII COS IIII)
Reference:
Mattingley, H. & Sydenham, E.A., "Roman Imperial Coinage", Volume 3 (RIC), p142, nr. 929
Sear, David R., "Roman Coins and their Values" (RCV Millennium Edition), Volume 2, p223, nr. 4192
Cohen, H, "Descriptions Historique des Monnaies frappees sous l'Empire Romain" (C), Volume 2, p323, nr. 543
Van Meter, D., "Handbook of Roman Imperial Coins", p138, nr. 77, variety with Ol/15, and Libertas stg left.
Suarez, R., "Encyclopedia of Roman Imperial Coins" (ERIC),  p116, nr.183, corrected (B09, O22, R095, T132)
Quality: Obverse Very Fine-, Reverse: Fine