Constantine I AE Follis. 320 AD. Trier. 

CONSTAN-TINVS AVG, helmeted, cuirassed bust right
VIRTVS-EXERCIT, standard inscribed VOT XX, captive 
seated on either side

dot PTR in ex. 

RIC VII Trier 266, rated R3. 

Used with permission of TimeLine Originals (www.time-lines.co.uk), September, 2009