Signedplated on front panel, top center: AMRAD / VARIOMETER SHORT WAVE TYPE D. / American Radio and Research Corporation / New York, N.Y. / Medford HIllside, Mass.
on box label: AMRAD / SHORT WAVE VARIOMETER 2300 / Manufactured and guaranteed by the / American Radio and Research Corporation / Medford Hillside, 57, Mass. / New York District Office / 21 Park Row / Chicago District Office / 608 S. Dearborn St.
stamped on side of box: AGAR / ... / AGAR MFG. CORPORATION, Medford, Mass.
ProvenanceCruft Laboratory, Harvard University.