The standard on the reverse of this coin has an interesting design not usually found on the pole. There are three round objects with four points coming out of each. I seem to remember seeing similar things on a few LRB's in the past, perhaps on VIRTVS EXERCIT types. These are probably just a different rendition of "Phalera, which are sculpted discs which were awarded for various military exploits." Below is a Vetranio with a labarum which shows the circular phalera.
Magnentius
A.D. 350-3
21x22mm 4.8gm
DN MAGNENTIVS P F AVG; rosette-diademed, draped, cuirassed bust right.
FELICITAS REIPVBLICE; Emperor standing left holding Victory on globe in right hand and labarum.
In ex. RSLG
RIC VIII Lyons 112