Tiberius II Constantine. AD 578-582. AV Tremissis. Sicilian mint. 1.4 g. 

dm TIb CONSTANT PP AG, pearl diademed, draped, cuirassed bust right.
VICTOR TIBERI AUG, cross potent. 
Mintmark CONOB.

Sear SB 472A; MIB III, N14.
Rare.

With permission of Emporium Hamburg - Auction 81, Lot 531, Oct 2018.

Note, there are other tremisses with this reverse, but 
this is the only one with TIb in the obverse legend.