Constans II and Constantine, AR Hexagram, 23 mm, 6.39 g. 
AD 641-668. Constantinople. 

DN CONSTANTINUS C CONSTANS, Crowned and draped busts of 
Constans with long beard on the left, and Constantine IV, 
beardless on the right, cross between their head.
DEUS ADIUTA ROMANIS, cross potent on globe and three steps; B 
in right field.
 
Sear Byz 996: DOC 55; MIB 150.

With permission of Leu Numismatik AG auction 10, Lot 2426, Oct. 2021.