The 8C9-438-X41S11 from Reactel is a Band Pass Filter with Frequency 417.5 to 458.5 MHz, Bandwidth 41 MHz, Center Frequency 438 MHz, Insertion Loss 0.65 dB @ CF, Rejection 35 dB @ 470 MHz. Tags: Module with Connectors, Cavity Filter. More details for 8C9-438-X41S11 can be seen below.