The RI2528BSfm-034042 from ZTS Technologies is a RF & Microwave Isolator with Frequency 3.4 to 4.2 GHz, Average Power Forward 100 W, Average Power Reverse 20 W, Insertion Loss 0.5 dB, Isolation 20 dB. Tags: Module with Connector, Coaxial Isolator. More details for RI2528BSfm-034042 can be seen below.