The FQ30109-3 from Sinclair Technologies is a Band Stop Filter with Stopband Frequency 406 to 512 MHz, Insertion Loss 0.6 dB, Power 350 W, VSWR 1.50:1, Operating_Temperature -30 to 60 Degree C. Tags: Module with Connectors, Rack Mount, Cavity Filter. More details for FQ30109-3 can be seen below.