The Tetrobol denomination
A Tetrobol is an ancient Greek denomination worth 4 obols - 2/3rds of a drachm.

It was struck in both bronze and silver.
(1) Histiaia
An AR Tetrobol struck c. 267-146 BC in Histiaia
Obverse: Head of nymph Histiaia right with wine-wreath

Reverse: Nymph Histiaia seated right on stern of galley, holding stylis; ornate apluster; IΣTI_AIEΩN, trident below

Diameter: -
Die Orientation: -
Weight: 2.2 g
No notes for this coin
BMC Central p. 129, 52; SGCV I 2498 var.
An AR Tetrobol struck c. 185-168 BC in Pella | Amphipolis
Obverse: head of Maenad right wreathed with vine leaves and grapes, wearing necklace and earrings

Reverse: stern of galley right, star above; MAKE / ΔONΩN, M?

Diameter: -
Die Orientation: -
Weight: 1.9 g
No notes for this coin
SGCV I 1384, SNG Cop 1292
(3) Phaselis
An AR Tetrobol struck c. 500-440 BC in Phaselis
Obverse: Prow of galley right; uncertain controlmark below

Reverse: Stern of galley left; ΦAΣ

Diameter: -
Die Orientation: -
Weight: 3.4 g
No notes for this coin
SNG von Aulock-; Cf Heipp-Tamer 72
An AR Tetrobol struck 323-315 BC in Amphipolis
Obverse: head of Apollo wearing tainia right

Reverse: horseman riding right; ΦIΛIΠΠOY, M in wreath

Diameter: -
Die Orientation: -
Weight: 2.52 g
Struck by Philip III in the name of Philip II
Le Rider pl. 45, 33; SNG ANS 625-7; SNG Alpha Bank 300