Watch List notes:

Attica, Tetradrachm, Athens, After 449 BC; AR (g 17,03; mm 23; h 9); Head of Athena r., wearing Attic helmet decorated with three olive-leaves and a palmette, Rv. AΘE, Owl standing r.; behind olive spring and crescent, at r., countermark. All within incuse square. SNG Copenhagen 31 ff.
Very fine.