The UIYBDC5377A from UIY Inc. is a RF & Microwave Circulator with Frequency 225 to 400 MHz, Average Power Forward 120 W, Average Power Reverse 120 W, Insertion Loss 0.8 to 1.2 dB, Isolation 14 to 18 dB. Tags: Drop-in Circulator. More details for UIYBDC5377A can be seen below.