Probus AV aureus. Siscia. AD 277. 20.45mm, 6.24 g.

Obv: IMP C M AVR PROBVS AVG, laureate, draped and cuirassed bust right, seen from the back.
Rev: SECVRITAS SAECVLI, Securitas seated left, holding 
sceptre in right hand, head resting on left hand. 

Mintmark SIS.

RIC 594; Cohen 629, Sear 11919.

With permission of TimeLine Auctions 
(www.timelineauctions.com), Oct. 2016