Patrai Tetrachalkon, very rare

Achaia, Patrai. AE Tritemorion or Tetrachalkon (20 mm, 3.41 g), c. end 40s BC.
Obv. Helmeted and draped bust of Athena right.
Rev. APICTAPXOC ΔAMWNOC ΠATPЄWN, Poseidon striding right, holding dolphin in left and thrusting trident with his right; to left, Patrae monogram.
BMC 5var; SNG Fitzwilliam 3563; BCD Peloponnesos 515.

Very rare and very fine.