A very nice piece.
Obverse : bust of emperor in laurel wreath with drapery on left shoulder, to right, in rim legend:
IMP TRAIANO AVG GER DAC P M TR P.
Reverse: War trophies stand on base, shield and spears at base, surrounded by legend:
COSV P PSPQ R OPTIMO PRINC
Silver, diameter 18 x 19 mm, weight 3.1 g, axis 6 h.