Watch List notes:

BOEOTIA, Federal Coinage. Circa 338 - 300 BC. Half chalkous (Bronze, 15.5 mm, 3.06 g, 12 h), Thebes. Boeotian shield; club across upper half . Rev. BOIΩTΩN Nike standing left, holding a patera in right hand and trident in left. BCD Boiotia 145. Imhoof-Blumer 33. Extremely rare half chalkous. About very fine.
From the collection of J. Aiello.

While the chalkous denomination with the shield/trident types is quite common, this half chalkous denomination is extremely rare.