The RFSL3121 from RF-CI is a RF & Microwave Isolator with Frequency 400 to 450 MHz, Average Power Forward 200 W, Average Power Reverse 20 W, Peak Power Forward 1 kW, Insertion Loss 0.3 to 0.4 dB. Tags: Module with Connector, Coaxial Isolator. More details for RFSL3121 can be seen below.