The NDC-4451 from Stellant Systems is a RF & Microwave Circulator with Frequency 4.4 to 5.1 GHz, Average Power Forward 2 W, Peak Power 15 W, Insertion Loss 0.3 to 0.5 dB, Isolation 20 to 23 dB. Tags: Drop-In, Drop-in Circulator. More details for NDC-4451 can be seen below.