This is a known Slavey reproduction of a unique gold coin. This copy is usually silver (tin) but this one looks bronze, with a fake patina.
Galerius
A.D. 307- 308
36mm 14gm
GAL MAXIMIANVS AVG VII CONS S; Laureate bust right, in consular robe holding globe.
IOVI CONSERVATOR AVGG; Jupiter standing left, holding thunderbolt and sceptre.
In ex. • S• M • S• D • (the real mintmark is • SM • SD • )
Cf. RIC VI Serdica 27