Watch List notes:

Heraclius. 610-641. AE follis (6.76 g). Constantinople, Dated year 22=A.D. 631-2. Heraclius on left, and Heraclius Constantine on right, standing facing, cross between their heads. Heraclius wears crown and military dress and holds long cross. His son wears crown and chlamys and holds globus cruciger / large M, ANNO to left, chi-rho above, XXII to right; CON in exergue. Countermark. SBV 810. aVF. Scarce. 

Reverse countermark: Class 1 Type 1 var; according to W. Schulze & T. Goodwin, Countermarking in 7th Century Syria. Last countermarked coin of Heraclius. Scarce! aVF.