The ZFBP-400K-S+ from Mini Circuits is a Band Pass Filter with Frequency 0.35 to 0.45 MHz, Center Frequency 0.4 MHz, Insertion Loss 1.1 to 3 dB, Upper Rejection 19 to 34 dB, Lower Rejection 20 to 67 dB. Tags: Module with Connectors, Lumped Component Filter. More details for ZFBP-400K-S+ can be seen below.