The T-3S13U-40 from Teledyne Microwave Solutions is a RF & Microwave Isolator with Frequency 3.7 to 4.2 GHz, Average Power Forward 50 W, Average Power Reverse 2 W, Insertion Loss 0.25 dB, Isolation 25 dB. Tags: Module with Connector, Coaxial Isolator. More details for T-3S13U-40 can be seen below.