The 2580 from KR Electronics (A Division of NIC) is a Low Pass RF Filter with Frequency DC to 30 MHz, Stopband Frequency 43.5 MHz, 3 dB Cutoff Frequency 30 MHz, Lower Rejection 40 [email protected] MHz, Upper Rejection 0.2 [email protected] MHz. Tags: Plug In. More details for 2580 can be seen below.