Watch List notes:

THE ROMAN EMPIRE
Constantine I augustus, 310-337

Half argenteus, Treveri 310-313, AR 1.55 g. IMP CONSTANTINVS AVG Laureate and cuirassed bust r. Rev. VIRTVS – MILITVM Four-turreted camp gate. In exergue, PTR. C 707. RIC 728.
Very rare. Light iridescent tone, a flan crack at one o'clock
on obverse, otherwise extremely fine