Countermark

https://rpc.ashmus.ox.ac.uk/countermark/967 
GIC 850 i
ΚΚ (on silver coins)
rectangular 
 

Coins with this countermark

Number Image TypeNumber CoinNumber VolumeNumber
RPC I, 3637 Show 3637 2 1
RPC I, 3637 Show 3637 5 1
RPC I, 3637 Show 3637 6 1
RPC I, 3637 Show 3637 7 1