The SMI-3540 from Sierra Microwave Technology is a RF & Microwave Isolator with Frequency 35 to 40 GHz, Average Power Reverse 2 W, Insertion Loss 1 dB, Isolation 16 dB, Operating Temperature -54 to 85 Degree C. Tags: Module with Connector, Coaxial Isolator. More details for SMI-3540 can be seen below.