This used 50 million Yugoslav dinar note is a replacement banknote issued by the National Bank of Yugoslavia. It is a red, purple, orange, and white note that is dated 1993, bears the signature of Dafina Milanovic, and measures 150 mm x 72 mm. Its obverse side honors the Serbian physicist Mihajlo Pupin, one of the founding members of the National Advisory Committee for Aeronautics (NACA) which later became NASA. Its reverse side features the telephone exchange building in Belgrade. Though the note does not have a security thread, it has a square pattern watermark. The details of this note have been verified and TAP Authenticated by Banknote World experts.