The PIF-21.4 from Mini Circuits is a Band Pass Filter with Frequency 18 to 25 MHz, Bandwidth 7 MHz, Center Frequency 21.4 MHz, Insertion Loss 0.05 to 0.72 dB, Rejection 20 dB @ 150 MHz. Tags: Plug In, Drop-In. More details for PIF-21.4 can be seen below.