The 2578 from KR Electronics (A Division of NIC) is a Low Pass RF Filter with Frequency DC to 60 MHz, Stopband Frequency 69.3 MHz, 3 dB Cutoff Frequency 60 MHz, Lower Rejection 40 [email protected] MHz, Upper Rejection 4 [email protected] MHz. Tags: Plug In. More details for 2578 can be seen below.