A nice piece in a dark patina.
Well readable details.
Obverse: bust of empress in drapery, to the right, in the rim legend:
FAVSTINA AVGVSTA
Reverse: Hilaritas standing left, holding a large palm leaf and a horn of plenty, in the rim legend:
HILARITAS
Silver, diameter 17.5 x 18 mm, weight 3.1 g , axis 6 h.