Note: This coin was mis-described by the seller as RIC 148.
RIC 148 does not have a break in the reverse legend.
This coin is a RIC 188 var. 
The information has been corrected below.

HJB-Constantine II as Caesar, Follis. Item number: 150048568778  
 
Winning bid: US $20.00   
Ended: Oct-26-06 09:44:31 PDT 
Seller: hjb-ancientcoins

Constantine II as Caesar, Follis, Follis, Lugdunum, 321 AD, 3.20g. 
 
Obv: CONSTANTINVS IVN NC, laureate, draped, cuirassed bust right, seen from the back
Rx: BEATA TRAN-QVILLITAS, globe on altar inscribed VO TIS XX in 3 lines, 3 stars above. 
C-R across fields.
Mintmark PLC
RIC VII Lyons 188 var (rev break, altar legend break, mint mark)