The CLPFL-0400 from Crystek Corporation is a Low Pass RF Filter with Frequency DC to 400 MHz, Insertion Loss 0.07 to 0.65 dB, Rejection 1.27 to 54.08 dB, Power 4 W, Return Loss 16.30 to 44.12 dB. Tags: Connectorized, Butterworth Filter. More details for CLPFL-0400 can be seen below.