The RFSL6858 from RF-CI is a RF & Microwave Isolator with Frequency 3.4 to 4.2 GHz, Average Power Forward 50 W, Average Power Reverse 20 W, Peak Power Forward 0.5 kW, Insertion Loss 0.3 to 0.4 dB. Tags: Module with Connector, Coaxial Isolator. More details for RFSL6858 can be seen below.