I have always wanted a Severus with this neptune reverse. I have lost out on a few but this one popped up from a international vcoins dealer at one heck of a reasonable price. I also fell in love with the portrait, which I think is one of the nicest I have seen of him in awhile.
This is the sellers photo, which was better then mine I attempted. The neptune looks more detailed in-hand.
Septimius Severus (193-211 AD)
O: SEVERVS - PIVS AVG, Laureate head right.
R: PM TRP XVII - COS III PP, Neptune standing left, leaning on raised right leg set on rocks and holding trident.
Rome, 209 AD
RIC 228 / Cohen 529/BMCRE 003