The 2512 from KR Electronics (A Division of NIC) is a Low Pass RF Filter with Frequency DC to 4.2 MHz, Stopband Frequency 17 MHz, 3 dB Cutoff Frequency 4.2 MHz, Lower Rejection 45 dB@17 MHz, Upper Rejection 0.1 dB@17 MHz. Tags: Plug In. More details for 2512 can be seen below.