Countermark

https://rpc.ashmus.ox.ac.uk/countermark/822 
GIC 703
monogram A with bar above (As?)
shaped 
4 x 2.5 mm 
the monogram could be read as{AS} (the denomination) 

Coins with this countermark

Number Image TypeNumber CoinNumber VolumeNumber
RPC I, 1289 Show 1289 3 1
RPC I, 1289 Show 1289 22 1
RPC I, 1289 Show 1289 22 1
RPC I, 1289 Show 1289 12 1
RPC I, 1289 Show 1289 13 1