As - Drusus Caesar IMP T CAES DIVI VESP F AVG P M TR P P P COS VIII RESTITVIT

This is a restitution issue — struck by Titus in 80–81 AD to reissue coinage of Drusus Caesar, who had died nearly fifty years earlier in 23 AD under circumstances that Tacitus considered suspicious, likely poisoning orchestrated by Sejanus. Restitution series under the Flavians were a deliberate political act, connecting the new dynasty to the prestige of Julio-Claudian predecessors and signaling continuity of imperial tradition after the chaos of 69 AD.

The original Drusus as had been struck under Tiberius, posthumously. Titus reissuing it a generation later is the coin's entire reason for existing.