The RPG FS-Z 500 | 3593.3273.02 from Radiometer Physics GmbH is a Spectrum Analyzer Extender with Operating Frequency 325 to 500 GHz, LO Frequency 9.02 to 13.88 GHz, Conversion Loss 50 dB. More details for RPG FS-Z 500 | 3593.3273.02 can be seen below.