The MMCCC520A from Mesa Microwave is a RF & Microwave Circulator with Frequency 170 to 300 MHz, Bandwidth 10 to 30 MHz, Average Power Forward 300 W, Average Power Reverse 300 W, Insertion Loss 0.5 dB. Tags: Module with Connectors, Coaxial Circulator. More details for MMCCC520A can be seen below.