Constans II or Constantinus IV tremissis?

[Luuk S]

Hi all,
This week i received this nice tremissis, which was sold as a Constans II. However, i noted that the Constantinus IV tremissises have the same obverse and reverse
How can one tell them apart, and which one do I have? Thanks in advance!

Weight: 1.41 g
Obverse: dN CONSTANTINuS PP AV
Reverse: VICTORIA AVGuS
Mintmark: CONOB

Gr Luuk

[Simon]

Constantinus IV Do you mean  Constantine IV?  If so, Sear says  the sons coinage  have blundered or abbreviated obverse legends and tend to be of a cruder style.
 No clear cut answer.

[Luuk S]

Yes Constantine IV. It doesn't appear crude or blundered to me, so that would mean that its indeed a Constans II?

[byzcoincoll]

It is a Constans II tremissis. They are not always distinguishable, but yours shows clear stylistic features of Constans II coinage.

[Obryzum]

I agree with byzcoincoll.  The reverse lettering is typical of Constans II.  Especially the oversized B in CONOB.