The 2157-40-10-50 from KR Electronics (A Division of NIC) is a Band Pass Filter with Frequency 38 to 42 MHz, Bandwidth 4 MHz, Center Frequency 40 MHz, Insertion Loss 1 dB, Rejection 40 dB. Tags: DIP, Lumped Component Filter. More details for 2157-40-10-50 can be seen below.