The TRFB4-4604-B5F7 from ETL Systems is a Impedance Matching Pad with Frequency 500 MHz to 2.5 GHz, Input Power 5 W, Operating Temperature 0 to 45 Degree C, Storage Temperature -20 to 75 Degree C. Tags: Module with Connectors, 50 to 75 Ohms. More details for TRFB4-4604-B5F7 can be seen below.