Caius and Lucius, AE of Pergamon, Mysia.3.07 gr.

KAISARA PERGAMHNOI, bare head of Caius Caesar right.
L KAI[SARA] DHMOFWN, bare head of Lucius Caesar right. 

RPC 2365 (this coin); SNG BN 2038.

Courtesy of Helios Auction 5, June 2011