The WVI-3800M-800BW01 from Wevercomm is a RF & Microwave Isolator with Frequency 3.4 to 4.2 GHz, Average Power Forward 50 W, Average Power Reverse 10 W, Insertion Loss 0.4 dB, Isolation 20 dB. Tags: Module with Connectors, Coaxial Isolator. More details for WVI-3800M-800BW01 can be seen below.