Watch List notes:

ARABIA, Southern. Saba'. Late 4th–mid 2nd centuries BC. AR nṣf – Unit (14mm, 5.37 g, 9h). Imitating Athens. Helmeted head of Athena right; N (in retrograde South Arabian; mark of value) on cheek / Owl standing right, head facing; [olive spray and crescent to left]; all within incuse square. Van Alfen, Studies, Group SII.A, 68a (O54/R57 – this coin); CAF 1.1i; Huth 160–1; SNG ANS 1455; HGC 10, 720. VF, lightly toned, minor porosity, light deposits on reverse.

Ex Classical Numismatic Auctions XV (5 June 1991), lot 271.