The ZXLF-K551+ from Mini Circuits is a Low Pass RF Filter with Frequency DC to 0.55 GHz, Stopband Frequency 1.14 to 18.5 GHz, Insertion Loss 1.5 to 3 dB, Rejection 11 to 24 dB, Upper Rejection 11 to 24 dB @1140 to 18500 MHz. Tags: Module with Connector, Reflectionless Filter. More details for ZXLF-K551+ can be seen below.