The VCI-3742 from VidaRF is a RF & Microwave Isolator with Frequency 3.7 to 4.2 GHz, Average Power Forward 50 W, Insertion Loss 0.3 dB, Isolation 25 dB, Operating Temperature -54 to 85 Degree C. Tags: Module with Connector, Coaxial Isolator. More details for VCI-3742 can be seen below.