★ Dramatic overstrike ★

Heraclius, with Heraclius Constantine (610-641) AE half follis, issued 630-40. Constantinople, 3.65g, 18-25mm.
Obv: Crowned figures of Heraclius, in military dress, holding long cross, and Heraclius Constantine, holding globus cruciger, standing facing.
Rev: Large K; cross above, A/N/N/O [year].
SB 815, overstruck on SB 815, officina A.
The off-centre strike allows us to discern military dress on both the overtype and the undertype, indicating SB 815 for both. (It does not appear to be a flip-over double strike.) The weight indicate a year in the 630s. An interesting coin, and far from common.