The TRE-6.1-3.9 from GeoSync Microwave is a Test Loop Translator with Downlink Frequency 3.625 to 4.2 GHz, Uplink Frequency 5.85 to 6.425 GHz, LO Frequency 2.225 GHz, Attenuation Adjustment Range 30 dB. Tags: Single Band. More details for TRE-6.1-3.9 can be seen below.