Countermark

https://rpc.ashmus.ox.ac.uk/countermark/825 
GIC 706
Λ
circular 
5 mm 
Thessalonica (Macedonia)
GIC had Δ or Α? This was without sight of image. Coin 29 of RPC I, 1561 shows it as likely Λ as there doe not appear to be a bottom bar for a Δ 
List of countermarks View on a map

Coins with this countermark

Number Image TypeNumber CoinNumber VolumeNumber
RPC I, 1561 Show 1561 29 1