Watch List notes:

Ancient Coins, Ancient Greek Kingdoms, Bactria, Heliokles (c.145-140 BC), tetradrachm, diad., dr. bust r., rev. ΒΑΣΙΛΕΩΣ - ΗΛΙΟΚΛΕΟΥΣ – ΔΙΚΑΙΟΥ, Zeus standing facing, thunderbolt in r. hand, monogram below, sceptre in l. hand, wt. 16.75gms. (HGC.12.169, var.), very fine
*ex Baldwin's vault
The monogram appears to be an unlisted variety.
(200-250 GBP)