Countermark

https://rpc.ashmus.ox.ac.uk/countermark/291 
GIC 162
ϹΑΡ | Β, bust of young Caracalla r., in dotted circle. on obverse
circular 
9.5 mm 
On coins of c. 25-26 mm. Following Johnston that the bust is of a young Caracalla 

Coins with this countermark

Number Image TypeNumber CoinNumber VolumeNumber
Show 233
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Show 133