The Biunx denomination
The biunx - two uncia - was a rarely used denomination during the Roman Republic.

It was used for both Aes Grave coinage and for struck coins.

It corresponded roughly to the sextans, which was also valued as 2 uncia, but the sextans was used when asses were valued at 12 uncia, and the biunx when assses were valued at 10 uncia.
Biunx

(1) Luceria 211-200 BC
Obverse: Veiled and wreathed head of Ceres right, ●●
Reverse: Scallop shell, LO / VCERI
Ref: HN Italy 681, SNG ANS 708, SNG BnF ...