The SMD1300-T0390 from Mercury Systems is a RF & Microwave Isolator with Frequency 3.6 to 4.2 GHz, Average Power Forward 5 W, Average Power Reverse 1 W, Insertion Loss 0.5 dB, Isolation 20 dB min.. Tags: Surface Mount, Surface Mount Isolator. More details for SMD1300-T0390 can be seen below.