Countermark

https://rpc.ashmus.ox.ac.uk/countermark/1353 
GIC
monogram ΚΑ
incuse 
5 mm high 3.5 mm wide at widest point 
 

Coins with this countermark

Number Image TypeNumber CoinNumber VolumeNumber
RPC I, 1802A Show 1802 5 1
RPC I, 1802A Show 1802 4 1