The SDC-1618 from Sierra Microwave Technology is a RF & Microwave Circulator with Frequency 1.6 to 1.8 GHz, Average Power Forward 100 W, Average Power Reverse 4 W, Peak Power 1000 W, Insertion Loss 0.5 dB. Tags: Drop-in Circulator. More details for SDC-1618 can be seen below.