Byzantine Empire, Constantine IV, Heraclius, and Tiberius, 15 July 668 - 10 July 685 A.D.
BZ99098. Bronze half follis, cf. DOC Online BZC.1971.37.11; Hahn MIB III pl. 37, 100; Morrisson BnF pl. LX, 14/Ct/AE/08; SBCV 1198a, F, maroon and green patina, scratches, earthen deposits, overstruck with significant undertype effects, 3.772g, 21.3mm, 135o, 3rd officina(?), Carthage (near Tunis, Tunisia) mint, facing busts of Constantine IV (in middle), Heraclius (on left) and Tiberius (on right), each wearing crown with cross and chlamys; reverse large K (20 nummi), cross potent left, Γ(?) right; from the Robert Wachter Collection; extremely rare, second known specimen, the only other specimen is in the Dumbarton Oaks Collection
All the references given refer to the same single specimen, the only other specimen known, currently in the Dumbarton Oaks Collection (added post publication but available online).
Click here to see DOC specimen. Sear describes the reverse with a K monogram and a T in the right field. Hahn and Morrison omit descriptions but provide photos. Dumbarton Oaks Collection Online correctly describes the coin with an plain K and a Γ, for the third officina, in the right field. The symbol in the right field on our specimen is obscure due to undertype effects, but the our coin appears to have been struck with the same dies.