Il like thos coins to with both kings could not wait for the post to show the coin to you my pictures/ vendor pictures BYZANTINE Æ FOLLIS of MICHAEL II & THEOPHILUS 820- 829 AD CONSTANTINOPLE MINT 5.9 GR & 23,20 MM Michael II the Amorian, with Theophilus. 820-829. Constantinople mint. Struck 821-829. Crowned facing busts of Michael, wearing chlamys, and Theophilus, wearing loros / Large M; cross above, X/X/X to left, N/N/N to right; A below. DOC 8; SB 1618 (Michael I and Theophylactus).
Very nice example! These large follis are always a joy to own and when you have Father and Son on the obverse, they are a doubt treat!
I've got one that I posted on the other thread. Not quite as nice as yours but has a glossy black patina.