The 2157-20-5-50 from KR Electronics (A Division of NIC) is a Band Pass Filter with Frequency 19.5 to 20.5 MHz, Bandwidth 1 MHz, Center Frequency 20 MHz, Insertion Loss 3 dB, Rejection 40 dB. Tags: DIP, Lumped Component Filter. More details for 2157-20-5-50 can be seen below.