Very rare obverse legend! Apparently only the 5th known specimen of this exact type!
Obverse: radiate, cuirassed and draped bust right, seen from back, legend:
IMP C M AVR PROBVS INVICT AVG;
Reverse: Sol in spread quadriga, holding globe and whip, legend:
SOLI INVICTO; In exergue KAΔ
Silver, diameter 22-23 mm, weight 3,68 g, axis 12 h.
From the collection of a true connoisseur of Probus’ coinage