Countermark

https://rpc.ashmus.ox.ac.uk/countermark/341 
GIC 217
empress, head r.
oval 
8 x 6 mm 
Prusias ad Hypium (Bithynia)
Price "Countermarks at Prusias ad Hypium", NC 7 (1967), 37-42, at p. 37, 5 (pl. 3, 5) identified the portrait as Faustina II 
List of countermarks View on a map

Coins with this countermark

Number Image TypeNumber CoinNumber VolumeNumber
RPC II, 687 Show 687 7 2
Show 104
Show 148