Can someone confirm this is a posthumous Constantine? [solved]

I'd like to know if this is Infact a veiled Constantine the first. 

Yes, it is.

Constantine I issued under Constantius II, reverse VN MR with veiled figure standing.

I'm not sure what mintmark letters I'm seeing, the first two look SM but the rest…

SMANB, Antioch mint, officina 2 :

https://www.nummus-bible-database.com/monnaie-98121.htm

🙂 

Thanks for the mintmark.

Then, it is here asN#134808  .

Thanks everyone for letting me know what I have :)