The 2157-30-5-50 from KR Electronics (A Division of NIC) is a Band Pass Filter with Frequency 29.25 to 30.75 MHz, Bandwidth 1.5 MHz, Center Frequency 30 MHz, Insertion Loss 3 dB, Rejection 40 dB. Tags: DIP, Lumped Component Filter. More details for 2157-30-5-50 can be seen below.