The IC 4.3 aat from TKI-Ferrit is a RF & Microwave Isolator with Frequency 4.2 to 4.4 GHz, Average Power Reverse 1 W (Load Power), Insertion Loss 0.3 dB, Isolation 25 dB, Operating Temperature 0 to 70 Degree C. Tags: Module with Connectors, Coaxial Isolator. More details for IC 4.3 aat can be seen below.