Constantine I AE Follis. Ticinum, 320-321 AD. 

Obv: CONSTAN-TINVS AVG, laureate head right. 
Rev: D N CONSTANTINI MAX AVG around VOT XX crescent in three
lines within wreath. 

Mintmark ST
RIC VII Ticinum 167

Courtesy of TimeLine Originals (www.time-lines.co.uk), March, 2011