The CNA-3742 from Stellant Systems is a RF & Microwave Circulator with Frequency 3.7 to 4.2 GHz, Insertion Loss 0.3 dB, Isolation 23 dB, Operating Temperature -20 to 65 Degree C. Tags: Module with Connector, Coaxial Circulator. More details for CNA-3742 can be seen below.