Well, its a nice portrait but the lack of legends wont make it easy to come up with a reference.
The reverse is the figure of pax and the end of the legend is visible (the VG of [PAX A]VG). Theres nothing in the fields and the mint mark is C so its quite a standard mass produced coin so the different references will all be the obverse legends and busts - one of the more key parts of the legend survives (IMP CAR... instead of IMP C CAR...) which narrows it down to the range RIC V-2 Camulodunum 303-307. All the numbers describe both the draped and the draped/cuirassed varieties, this appears to be draped and cuirassed.
Interestingly, the legend is not even - the AVG is very widely spread out, probably early on in the celators career (apparently they had someone cut the bust and someone else cut the legend). The letter before doesn't appear to be an S, so that would cut out RIC V-2 Camulodunum 307. There is ample space for the G, so that cuts out a few as well. Given the wide spacing, I see no reason for the celator to drop the F in PF, so my money is on RIC V-2 Camulodunum 303.
IMP CARAVSIVS PF AVG
RDC
PAX AVG
standing left / olive branch and vertical sceptre
C
RIC V-2, Camulodunum 303
It should be noted that a new RIC is coming out soon and also that the attribution of the C mintmark to Camulodunum is in question and often described now as the 'C mint'.
And Tenbobbit - that appears to be unofficial, but its hard to tell because all the earliest issues were in poor style. The reverse figure is Pax but the legend has been blundered (...V...VG). Perhaps thats an upside down A.