The IS-139 from MCLI is a RF & Microwave Isolator with Frequency 800 MHz to 2.5 GHz, Average Power Forward 30 W, Insertion Loss 0.8 dB, Isolation 17 dB, Operating Temperature 10 to 40 Degree C. Tags: Module with Connector, Coaxial Isolator. More details for IS-139 can be seen below.