The KTBC-301A from Kete Microwave is a RF & Microwave Circulator with Frequency 2 to 4 GHz, Average Power Forward 20 W, Insertion Loss 0.6 dB, Isolation 16 dB, Operating Temperature -30 to 70 Degree C. Tags: Module with Connectors, Coaxial Circulator. More details for KTBC-301A can be seen below.