Watch List notes:

P. Paetus, Rome Mint, 138 BC.
Helmeted head of Roma right, behind X;
The Dioscuri with spears riding on horseback to right, beneath P_PAETVS, in exergue ROMA
Crawford 233/1. Uneven, undersize flan. Minor scratch on the obverse. About very fine. Size: D: 19.5mm; 3.58g