The 2547-2000 from KR Electronics (A Division of NIC) is a Low Pass RF Filter with Frequency DC to 2 MHz, Stopband Frequency 4 MHz, 3 dB Cutoff Frequency 2 MHz, Lower Rejection 45 dB@4 MHz, Upper Rejection 1 dB@4 MHz. Tags: Module with Connector. More details for 2547-2000 can be seen below.