The SMI-4353 from Sierra Microwave Technology is a RF & Microwave Isolator with Frequency 4.3 to 5.3 GHz, Average Power Reverse 2 W, Insertion Loss 0.4 dB, Isolation 20 dB, Operating Temperature -20 to 65 Degree C. Tags: Module with Connector, Coaxial Isolator. More details for SMI-4353 can be seen below.