The JCD4200T4400G2-B from JQL Electronics is a RF & Microwave Circulator with Frequency 4.2 to 4.4 GHz, Average Power Forward 20 W, Insertion Loss 0.3 dB, Isolation 23 dB, Operating Temperature -30 to 70 Degree C. Tags: Drop-in Circulator. More details for JCD4200T4400G2-B can be seen below.