Countermark

https://rpc.ashmus.ox.ac.uk/countermark/806 
GIC 684
Ρ
circular (or slightly oval) 
6 mm 
 

Coins with this countermark

Number Image TypeNumber CoinNumber VolumeNumber
RPC I, 3341 Show 3341 5 1
RPC I, 3342 Show 3342 5 1