CONOB
The abbreviation CONOB can be found usually in the exergue on the reverse of many gold coins of Byzantium.
CONOB. Constantinopoli obryzum. The solidus weighed 1/72 of the Roman pound. "OB" was both an abbreviation for the word obryzum, which means refined or pure gold, and is the Greek numeral 72. Thus the exergue CONOB coin may be read "Constantinople, 1/72 pound pure gold." -- "Byzantine Coinage" by Philip Grierson

Specifications

Coin	Diameter	Alloy	Weight	Description
Tremissis	16.5 - 17.5	Gold	1.55	Radiate Head Right

Notes
Diameter = millimetres
Weight = Grams

Description
Obverse
Draped, cuirassed, and radiate bust of Maurince Tiberius facing right, with the legend
DN TIBERI PP AUG

Obverse
Cross potent, with legend:
VICTOR M AURI AUS
CONOB