The 2159-20-50 from KR Electronics Inc is a Low Pass RF Filter with Frequency DC to 20 MHz, Stopband Frequency 29.2 MHz, 3 dB Cutoff Frequency 20 MHz, Lower Rejection 40 dB@29.2 MHz, Upper Rejection 1 dB@29.2 MHz. Tags: Plug In. More details for 2159-20-50 can be seen below.